Operation: DEFIANT STAR

Operation: DEFIANT STAR was a long term campaign aimed at halting the advancing Covenant Remnant. Taking place across two dozen star sectors, it would involve significant manpower and numerous battles and smaller operations, as the UNSC faced the ever increasing threat of a Covenant pincer movement.
==Background==
===Remnant War===
The Remnant war had begun six months earlier with an undeclared attack on the colony of Greenwell, which was razed to the ground. Similarly, forces attacked several Sangheili colonies simultaneously. While skirmishes and raids by the Covenant Remnant were common, the Office of Naval Intelligence and Republic Justiciars had little idea of the true scale of the Remnant battle plans, or the forces at their disposal. 
===Blitzkrieg===
When the Covenant launched their assault, they used multiple blitzkrieg spearheads, with colossal fleets punching holes through the UNSC lines and penetrating deeply, leaving token forces to mop up. This tactic had allowed the Covenant to advance far, but were hampered when they encountered Slipspace Scrambler technology, preventing their quick advance and baring their unimpeded advance. The UNSC used this to their advantage, picking them out piece by piece, attempting to blunt their assault. Using this opportunity, the UNSC fortified world after world, meaning every strike turned into a bloody siege instead of a decisive victory. This needed to be changed, and quickly. 
===Pity's Flank===
The Prophet of Pity, a hedonistic and impatient individual, had quickly become bored of the speed of his fleet's conquest. Pity instead took the advice of his top officer, Malernus, and diverged off to the east of the main advance, seeking to flank the bulk of the UNSC's defences. Followed by one of the Remnant's appointed Pirate Princes, Mak Kur, his substantial force looked to be in position to quicken the advance once again. Securing his inner flank was the Prophet of Objection, taking a fleet with him. 
==Prelude==
The Covenant had not just blindly launched an assault on the UNSC, but rather spent months gathering intelligence, finding colony locations, locating UNSC strongholds and fleet positions. The Covenant knew their enemy well, and intended to disrupt him as much as possible. However, their own supply lines were going to be stretched dangerously thin, and this required them to survive by raiding the UNSC's own fuel supplies, as well as civilian fuel. 
While Pity was simply engaging in battle to appease his own appetites, Malearnus and Objection took a much more pragmatic approach to the coming battle. They established forward bases and supply caches, and begun sighting targets in preparation for the upcoming conflict. 
While the Argon Sector wasn't in the direct brunt of the Covenant's advance, the UNSC had taken measures to begun reinforcing the sector. Recently, they had strengthened the planetary defences of a number of key sectors, as well as building several supply bases to allow the UNSC to maintain a highly mobile warfare style, to assault a larger force. Defence of the 24 star systems in the Argon Sector fell upon Task Force Vengeance, a collection of 3 UNSC Battlegroups, including Battlegroup Axios, Thunderstruck and Sword of Damocles, and a large detachment from the UNSC Engineering Corps. Their closest backup was Task Force Reaver, which consisted of elements of the 11th Fleet held back in reserve, and the 16th Fleet, who were on approach to the Argon sector to finalize the reinforcement, though would only arrive a week after the initial invasion. 
Argon Sector itself was not of vital important as a strategic or tactical target, but by outflanking the bulk of the UNSC defence, the Covenant advance could well advance much deeper into UNSC territory, causing horrendous damage to infrastructure and heavy civilian casualties. The sector was also home to nearly 20 million UEG citizens, whom the UNSC pledged to protect. 
==Battle==
===First Sighting===
The first inclination the UNSC had that the Argon Sector was under threat came at 0433 on April 9th. The UNSC Raven, a Minerva-class Prowler, was performing long-distance reconnaissance, when it intercepted high level communications between Objection and Malearnus. Sending this back to sector command, the local cyber intelligence branch decrypted the message to learn they were moving troops into position to strike across the Argon sector. Relayed to Argon defence command at Guinevere, Raven was tasked with shadowing the oncoming threat and reporting back, while Task Force Vengeance was ordered to move into advance positions against what would otherwise be overwhelming odds. Towing a small number of Orbital Defence Platforms, as well taking a number of ENGCORP mine laying vessels. 
===First Contact===
The Raven shadowed outlying scouts of the fleet, intending to find their ultimate position. Fanning out their search pattern, one of their probes discovered the vanguard of the invasion fleet. A battlegroup of warships was discovered at 0534 on April 9th, on course to Ankara, the most advanced position of Task Force Vengeance. Transmitting this information to the task force commander, Admiral Jeffrey Morecombe, the Raven moved to a more comfortable shadowing position and pursued them. The vanguard, which already out numbered Vengeance two to one, would arrive at Ankara in three hours. Beginning to evacuate the world, Morecombe ordered his fleet into defensive positions near the poles, while the orbital defence platforms would defend the major population centres. They lay a three dimensional minefield at the apex point of the vanguard's position, using telemetry provided by the Raven. 
As predicted, the enemy fleet arrived in three hours, dropping out of slipspace at 0901. Evacuation on Ankara was already well under way, but would take another three hours to evacuate the whole planet. Morecombe however, also had the problem that he could not simply throw all his ships into this defence, as more battles would follow, with no reinforcements until the 11th. He would have to withdraw before the enemy forces became too great. A force of 83 vessels dropped out of slipspace and as predicted, directly into a minefield. While they caused substantial casualties in the opening barrage, they had only knocked a dozen warships out of the battle. As the six defence platforms opened fire, the Covenant fleet pressed the attack. Despite attempts to discern the command vessel, interference prevented them accurately picking out their enemy. Supporting the defence platforms with indirect missile fire from behind satellites, since abandoned and used to cover themselves, or from behind one of the moons. The initial salvoes knocked out one of the carriers, and the front echelons, but once they reached firing range, half of the defence platforms were knocked out by energy projector fire. Moving to flanking positions, Admiral Morecambe attempted to halt the rapid and almost unimpeded advance, only to discover their true aim. They rushed forward to attempt a planetary invasion. Their carriers moved to orbiting positions over the planetary capital and destroyed the orbital elevators and space ports, halting the advance. Swarms of fighters eliminated the few evacuation craft remaining in orbit, while Vengeance's own fighters moved to cover the remaining few until they could jump out of system. Recognising their intent, Morecombe wasn't willing to give up Ankara without a fight. Keeping a number of his 'big guns' firing on the Covenant flank, he took a selection of heavier vessels and performed a slingshot manoeuvre around the planet, his ships entered 'knife fight' range where they held the advantage, managing to throw the Covenant ships back, and even knocking a carrier out, its engines failing and its torn hull falling into the sea. 
===Retreat===
Despite the success of the counter-attack, reinforcements were approaching the system at maximum speed, and they would be quickly overwhelmed if they stayed any longer. Using their brief window, they used any and all transport craft, including military vessels, to try to evacuate the colony. Just two hours into their battle, they withdrew, leaving thousands behind. Morecombe would evacuate his ships, towing the two surviving platforms out of the system and would drop of the refugees at Kiril, where supply ships would help evacuate them. Kiril itself was abandoned before the Covenant would find it. 
Morecambe would stage a number of fighting retreats for the next fifteen hours, going from system to system, attempting to slow their advance, long enough so the most populated worlds could be evacuated. Many smaller colonies were simply left to their fates, while others would be abandoned midway through the evacuation. Such events were poorly received by the civilian population, resulting in unrest on a number worlds, but Argon Defence Command could not disagree with this course of action. Such events would ultimately save a great many lives, though were poorly received. 
===Skirmish At Supply Base X-04===
Task Force Vengeance, running low on key supplies, would use a number of deep space supply bases to continually resupply and return to the fight, allowing them to operate for extended periods where as the enemy was continually forced to consolidate their position to refuel and resupply. After a staggered retreat, Vengeance enacted the Cole Protocol then returned to their nearest supply base, designated X-04. Unknown to them, the Covenant had captured on of their supply vessels and recovered a partially intact navigation computer, directing them to X-04. Arriving at the edge of the system, Vengeance had evaded detection by the Covenant, which had quickly surrounded X-04. Massacring the crew and preparing to loot the station of its substantial collection of fuel and nuclear weapons. Low on supplies, Morecambe couldn't resist a full scale battle, and instead planned to annihilate the Covenant forces surrounding it. Using the cyberwarfare facilities upon his lead Prowler, they remotely activated the store of nuclear charges on the base and remotely detonated it's substantial nuclear payload, the resulting fireball annihilating twenty Covenant ships. Now lower on supplies than ever, Vengeance would return to the fleet base at Guinevere to make their last stand. 
===Guinevere Encirclement===
The outlying systems around Guinevere had been overrun, forcing them into a boxed in position. Malearnus intended to surround them, so he could destroy them at leisure, while surrounding systems were pacified by splinter forces. Pity would go from world to world, bombarding them in a haphazard manner and leaving Objection to conquer and fortify them. In this manner, they took almost fourteen worlds. Pity was fine to leaving the boring task of siege-work to Malearnus while he engaged in his own desires. 
Only four star systems remained under the UNSC control, forcing Vengeance, now down to three quarters strength, to perform hit and run missions, attempting to slow the enemy through misdirection and guerilla warfare. This was only a holding action, as the three outlying star systems fell in time, leaving Guinevere. Their actions had bought them time to fortify the sector with a dozen orbital defence platforms, a vast and complex mine network, and substantial defensive positions on the ground. 
On April 11th, at 1432 local time, the Covenant moved into position around Guinevere, holding their fleet at the edge of the system, intent on starving Guinevere into submission. Occasionally, forays would head towards the planet, testing their defences. Such battles would end in casualties on both sides. Malearnus also sent his top commander to take the fuelling station. A hard fought battle resulted, escalating to a long range bombardment by the defence platforms to attempt to throw them back, while the UNSC desperate took as much fuel as they could from the automated station, before setting it to plunge into the atmosphere of the gas giant it orbited, dragging down two Covenant ships coupled with it. 
Malearnus, knowing he'd been denied the fuel necessary to continue the siege, decided to press the attack, to force the UNSC into action. Using the planet's moon as cover, his fleet punched a hole in their defences, in the process throwing Vengeance into disarray. His troops would launch a high speed drop pod assault, attempting to seize important structures quickly. Instead, they found themselves facing a heavily entrenched enemy, with close air support. His soldiers fought desperate battle to secure a foothold so as to allow reinforcements to land. While they secured landing zones, their casualties prevented them from pressing the assault, instead establishing their own defences in fear of a counter attack. Bringing in stationary weapons and artillery pieces, they instead chose to try and bombard the enemy into submission.
This siege turned into a bloody stalemate as the UNSC refused to budge an inch. Every time they managed to take a trench, defensive complex or a building, they found themselves quickly ousted by the counter attack. They instead elected to revert to bombarding positions into dust before advancing, but instead found themselves in a more dire situation, where the annihilated terrain made advance difficult, and the defenders, still alive and still prepared to fight, and still held the superior position. 
===Reaver Arrives===
Task Force Reaver arrived at the Argon sector on April 11th, at 2200. Knowing they were facing an oncoming invasion, they had specific orders to punch a hole through the encirclement surrounding Guinevere and resupply the beleaguered defenders. Knowing such an action was impossible as it stood, they initiated Operation: RED PYRE, intending to ambush the Prophet of Pity. Knowing they couldn't defeat his battlegroup in a straight up fight, they instead aimed to cause such horrendous casualties and mislead the survivors that Malearnus would be forced send ships to his aid. 
Tracking him to the world of Cordes, where he was busy terrorising a population for his own entertainment, believing himself safe from reprisals. Reaver would move into holding positions close to the edge of the system, with electronic warfare ships surrounding his fleet. Once in position, they opened fire, sending steams of missiles, magnetic slugs and nuclear munitions into his armada. Suddenly and inexplicably taking casualties, Pity was at first dismissive, until his officers intercepted radio communications that they were both heavily out numbered and surrounded. Using deliberately poorly encrypted messages, Reaver convinced Pity that they both out numbered and out gunned him, forcing him to call for help. 
Malearnus, exasperated by since, was forced to send a large number of forces to aid Pity. Reaver would leave a small rearguard to keep up the terror attacks, while the bulk would move to a secondary position and stick suddenly and violently at Malearnus' weakened encirclement. Now with a secured corridor of resupply, the defenders at Guinevere could breath a little easier. However, to maintain this, Reaver would have to go on the attack. Pulling out, they moved to conduct a new series of operations, intended to off balance and delay the Covenant. 
===Operation: DEVIL'S MOON===
Reaver, facing the implacable advance of Pity and Objection, had to stall for time, at least long enough for the 16th Fleet to arrive. To do this, they would divide into smaller units and perform clandestine warfare, attempting to stall their advance. 
Initially, Reaver would open the operation with hit and run strikes against their staging areas, damaging ships and inflicting casualties. As the Covenant began adapting tactics to halt this, reaver switched gears, instead attacking their supply convoys as they moved through slipspace, destroying vital supplies, including fuel and weapons, as well as attacking troop transports. Their attacks stretched their supplies thin, forcing them to postpone attacks and pull back to their defensive positions on Guinevere. Pushing the fleet to their limit, Reaver continued near unimpeded in their operations. This was teamed with their Prowlers laying minefields in their space lanes and around their fleet bases. These Prowlers would hamper the Covenant's ability to coordinate by jamming communications, or inserting false communications, leading them astray. 
===Operation: CRIMSON SHROUD===
As part of the continued effort to delay the enemy by attacking their rear echelons, Blackjack Company, a unit of elite Spartans, were withdrawn from their defensive positions elsewhere to wreak havoc. Simply given the orders of 'butcher and bolt', attacking targets of opportunity as they saw fit. Given carte blanche to act as he saw fit, commanding officer Ajax-013 would assign targets to his lieutenants, intended to off balance the already struggling Covenant. 
At Kiril, a force of Spartans entered the Covenant naval base with a stealth vessel and commandeering a communications satellite, issuing false orders to the entire front. This resulted into an entire fuel consignment being redirected to rendezvous with allied forces in an oort cloud, only to be stolen by the waiting warships of Task Force Reaver. 
Blackjack used their own stealth vessels to pursue and capture a number of cargo vessels in slispace transition, and replace their precious cargo with nuclear charges. Upon arriving at their destination, these vessels annihilated the waiting supply vessel and the ships guarding it. 
On the world of Thrace, spartans inserted in the midst of a powerful thunderstorm and approached an important listening post, intercepting UNSC communiques. Quietly exterminating the guards, they took the position as their own, and rewired it to gather intelligence on the Covenant, and left it to remotely feed them intelligence. 
The Spartans took to the tactic of capturing smaller Covenant vessels and using them as fireships, setting them on collision courses and programming their pinch fusion reactors to overload, or their slipspace drives to inexplicably activate, flash melting space stations, or using the gravitational force of a slipspace portal to tear warships in half. This shook the Covenant so much that the number of friendly fire incidents jumped massively, almost over night. 
Utilising remote beacons established to keep lines of communications open, the Spartans uploaded numerous and dangerous viral programs, designed to cripple any system they found their way into, propagate, and evolve. Any ship using these beacons was effected, and suffered catastrophic failures, some becoming lost as they suffered severe accidents such as slipspace drive failures, crashes with other ships or celestial bodies, or just life support failure, the crew freezing and suffocating. 
At Agrippa the Spartans deployed to the planet en-masse, sneaking into positions close to their vast slave-camps. Bringing in disassembled weapons, explosives and other pieces of equipment, they began to train the slaves to sabotage the factories they were made to work in, then began to train them to break into full insurrection. Small pockets of resistance turned into full scale resistance, as the former slaves entered open revolt, lead by Spartans from Blackjack. Such was the ferocity of the uprising, they briefly took back the planet, throwing the Covenant into full retreat. Capturing the carrier used to secure this world, they got the slaves off the planet and back to safety. 
In their most destructive operation, they waited until the Prophet of Objection became exposed, during an inspection of a newly built citadel complex to establish control over a conquered world. Blackjack crept into positions close to the complex before striking, suddenly and violently assaulting the Covenant forces in close quarters. Butchering their way through his forces, they took Objection by the throat and dragged him kicking and screaming back to their own ship. Left in disarray by the sudden capture of their leader, his forces pulled back. Taking Objection back to their ship, they spent weeks interrogating him, extracting information that would prove pivotal to their operations. 
===Pirates Unleashed===
Angered by the UNSC's ability to strike behind their lines with near impunity, Malernus decided to release Mak Kur, the pirate prince sworn to his service. Disliked by Pity, Mak Kur was violent, unpredictable and difficult to control. However, his ability to sow discord would allow Malernus to finally gain back to advantage. Mak Kur would immediately move from supporting positions to assaulting the UNSC on their own turf, penetrating deeper into UNSC lines than his masters had ever gotten. Reaver suddenly found themselves on the back foot as pirate forces began to engage them in clandestine warfare, using guerilla warfare, hit and run and sabotage, attacking the UNSC in weak points. They would continue their raids almost unmolested, up until Final Thorn. 
===Operation: FINAL THORN===
On the 16th, the Argon Sector was finally reinforced by the 16th Fleet. Linking up with Task Force Reaver, they splintered into multiple elements, taking back worlds previous brought under the control of the Covenant. Well supplied and on equal footing for numbers, 16th Fleet should of been capable of annihilating their enemy with ease. However, Mak Kur's pirates harassed them at every turn. Infinitely slippery, and capable of striking at their rear echelons, 16th's advance was slow and unsteady. 
Fleet Admiral Niels Vancamp, held back from relieving Guinevere, attempted to spread his forces out in order to entrap the pirates, but again they slipped the net. Finally making contact with the leaderless Fleet of Righteous Iconoclasm, their initial battles were hampered by repeated attacks by the pirates, forcing Vancamp to withdraw and devise a new plan. 
Utilising the specialists in Blackjack company, they used misdirection to lure the pirates into a trap. Blackjack left a trail of irresistible crumbs, including a stranded scout vessel, with a single corpse and vital intel, intercepted communications, battle plans detailing their line of supply and a partially destroyed supply vessel, directing them to the undefended supply base of the UNSC. Taking the bait, Mak Kur take his entire pirate fleet to loot it. 
Dropping out of slipstream space, he found the undefended supply base and approached it immediately. However, immediately the lack of supplies, or ships alarmed Mak Kur. That's when the trap was sprung. Trapped by a slipspace inhibitor, Mak watched as the entirety of the 16th fleet jumped in around him and opened synchronized fire. Trapped in the net, and locked by staggered crossfires, his fleet quickly capitulated and attempted to escape the trap. His agile fleet attempted to divert towards the cluster of planetoids, surrounded by bands of asteroids. The UNSC fleet elected to maintain their distance, firing with remorseless precision, every volley shattering the hull of one of his vessels. Hundreds of missiles were fired at a time, shredding warships with ease. Pressing their advantage, the UNSC pinned Mak Kur against the largest of the planetoids, an inhospitable ice world, and began to destroy the fleet piecemeal. Disabled ships, their engines failing, tumbled into the gravity well of the world, crashing into the planet, or punching through the dense ice layer and sinking into the sea below. Many more were torn asunder by the stress of orbital manoeuvres and enemy fire, while others were so totally obliterated their fragmentary hulls burned up in orbit. Many more ships would surrender, lowering their weapons and shields to abandon their position. Mak Kur himself was killed when his command cruiser was struck by no less than 400 missiles, the hull punctured and the reactor destroyed. While life boats were launched, most took their chances on the planet below, where the crew would inevitably freeze to death. The burning hulk of his flagship fell into the gravitational pull of the planet, where it broke up, its hull turning into a cloud of debris that proceeded to damage another two surviving vessels. 
All in all, the UNSC destroyed almost 70 ships, while disabling 19 and capturing 40, either through surrender or boarding actions. No member of Mak Kur's fleet escaped the ambush. While a few bands of pirates that fought under his banner survived, because they had not been part of his fleet during the ambush, they would cease to be a threat, as their numbers and equipment were far too low to be of any threat.
===Operation: TACIT SPECTRE===
Now in their strongest position yet, the 16th Fleet moved to alleviate the siege at Guinevere with a three pronged attack. Under the umbrella name of Operation: TACIT SPECTRE, his force would proceed to divide and conquer, turning the tide against the Covenant. 
The largest portion of the fleet, designated 'Force Z', which included most of her carriers and cruisers, proceeded straight to Guinevere, through the narrow passage established by Reaver days earlier. Despite running the gauntlet, the majority of the team made it to Guinevere, and just in time. Arriving on the 18th, Force Z arrived after a week of besiegement, reinforcing the struggling Task Force Vengeance. 
Vengeance had been reduced to just twelve ships, most of which bore some degree of damage, and all of which had little to no fuel left, and very little ammunition. All of their defensive platforms had been destroyed and their fighter squadrons had been reduced to only a few working airframe from multiple squadrons, formed into a small number of squadrons. On the ground, the defenders had begun to run low on food and ammunition grew scarce. They'd resorted to taking enemy weapons where they could and fighting hand to hand to hold back the enemy. Hastily organized civilian militias utilised improvised weapons to hold the enemy back wherever they could, using their own knowledge of the city to out flank them. Using any flammable liquid they could find, they created Molotov cocktails, bombarding advancing troops with the improvised grenades. Their surviving aircraft were abandoned, as fuel and ammunition had since ran out. 
Malearnus knew reinforcements would be arriving soon, but he was in no position to oppose them. Stretched thin by Reaver and Blackjack, and with Pity taking more and more of his ships to satiate his own bloodlust, Malearnus instead mved his ships back to bases they'd established in the system. When Force Z arrived, the effect was immediate and destructive. They ships rushed headlong, immediately re-securing orbital dominance. The Assault Carrier. Retribution dived headlong over the capital, leaving a three kilometre long trail of fire in its wake. Pulling a high-g manoeuvre over the city that stretched its structural strength to its very eliminated, it destroyed three CCS-class cruisers in as many minutes, utilising its primary and secondary gauss cannons and its secondary batteries, then proceeded to rain ordnance, troops and supplies down on the city, scouring the Covenant forces and relieving the ground forces. In orbit, Force Z pulled into defensive positions, knowing they held the range advantage with their superior number of big guns. 
Task Force Vengeance, at last relieved, pulled out of the system, retreating into UNSC space. Ships from Force Z would secure the supply route, and would continue to hold it as Guinevere was evacuated. Denied his prize, all Malearnus could do was sit and watch. Malearnus elected to quietly pull out of the system, leaving a small rearguard to maintain pressure against the defenders. 
The next element of the 16th Fleet was designated 'Force X'. This unit would mass together the most nimble vessels, including light cruisers, carriers, frigates, destroyers and several cruisers in support. Jumping into slipstream space, they headed towards a high value target deep behind enemy lines. Using intelligence gathered by Reaver and confirmed by Blackjack company, they headed towards their main supply base at Kiril. Transforming Kiril's industry into supplying their war machine. Destroying this infrastructure would set them back for weeks, and their supply network would effectively grind to a halt. Dropping out of slipspace on the opposite side of the system, they approached out of the sun. This gave them an advantage, as visual censors had difficulty picking them up, and the radiation emitted by the star would confuse any sensors looking at then. Doing this, they evaded enemy attention until it was far too late, and they launched their attack. Hitting the orbital supply station, they destroyed the defending vessels and cut the station off. Launching barrages of slugs and missiles at the surface with little restraint, they turned the refineries for making starship fuel into half a kilometre tall fireballs, and destroyed as many supply vessels as they could find. Much of the surface was reduced to molten slag under the bombardment and the extensive network of space stations towed into position were turned into a ring of debris six kilometres wide and one kilometre deep. Disappearing almost as quickly as they arrived, their attack destroyed any means of refuelling their vessels. 
The last unit, 'Force V', was made up of Prowlers, warships from Reaver and Blackjack company, was assigned to conduct a diversionary attack, that would establish the next phase of the battle. Force V headed deeper into Covenant held space, to their base of operations. slipping in under their orbital defence platforms, they began to attack the planet. A vital fortress world, it quickly came under orbital bombardment, softening up the defences before the orbital assault. The first wave, made up of ODST and Spartan forces, rocketed down on top of the fortifications in drop pods, capturing the outer ring of defences around the inner citadel. This paved the way for Force V's flagship, the UNSC Agamemnon, to come down into orbit. The Super Carrier disgorged vast amounts of fighters and dropships, bringing armour and artillery down onto the surface. Taking the shortest route to their target, an armoured force punched their way through the canyon network up to the citadel, supported by close air support and artillery. Once in range, several Mammoth siege platforms knocked down their defensive perimeter and knocked down the outer wall, allowing Marines to storm the breach. Members of Blackjack company tunnelled under the eastern wall, planting a huge explosive charge at the base of one of the towers and detonated it, bringing down the wall, and allowing the UNSC to open a second front. Fighting up the battlements, the UNSC painstakingly cleared each position. Finally taking the battle to the citadel, they cleared the fortress level by level until they at last secured it. Now in control of their primary fleet base, their previously silenced distress calls were now allowed to sound out. The UNSC rigged the citadel with explosives, and shifted the IFF tracking of their surviving defensive guns, so as to attack their own ships and then planted dozens of nuclear charges on the surface. Their trap set, Force V withdrew, leaving a smouldering wreck in their wake. 
Unable to ignore the pleas from his base of operations, Malearnus withdrew to secure it. Upon arrival, he discovered the UNSC had withdrew, but left important structures largely intact. Sensing a trap, he intended to advance cautiously, but Pity's suddenly arrival, in need of repairs after a poor encounter with Force Z, sprung the trap. Ignoring Malearnus, his ships went to dock, while his troops went to the surface to secure the conquered fortresses. His ships in orbit were rocked by the detonation of nuclear mines, with the forts on the ground disappeared in a ball of nuclear fire, tens of thousands of troops killed in a single blow. Though Pity survived, he was so shocked by this attack that he withdrew from the bridge of his ship and refused to leave his chambers. Malearnus took control of the survivors, and rallied to make his counter attack. 
===Operation: POISON ANGEL===
Vancamp needed more information on the enemy's movements, and their actions. Prowler reconnaissance was limited, and now that Malearnus had began to take charge of the whole front, their tactics shifted focus from mindless raiding to coordinated strikes, intelligence would be their most important edge. For this, he turned to Blackjack company. 
The UNSC knew the Covenant had a vital communications outpost in the Beta Sigma system, on a supposed 'death world'. Planet in question was referred to by explorers as 'Caustica', and was a literal hell. Possessed of a corrosive atmosphere, the planet also had high pressure, high background radiation, any rivers or lakes were even more corrosive. A little bit too close to the star, it was also dangerously hot. The communications outpost was positioned on top of a mountain, above the caustic atmosphere, and was near unassailable. Shielding prevented drop pod assault, while ranks of anti-aircraft turrets prevented aerial attack. Mission planners had considered bringing in several capital ships to perform close bombardment, but the risk of destroying the outpost itself was just too great. Instead, Blackjack company deployed to the jungle below, fitted with high-end armour designed for hazardous environments, backed up by reinforcements from the 10th Hazardous Environment Division, known as the Hellbringers. Advancing through the jungle, they encountered several patrols, eliminating them and setting the murderous environment dispose of the bodies. Advancing up the mountain under the cover of darkness, they accessed the base through its waste disposal system, creeping through the pipes until they were in the heart of the base itself. Quietly eliminating the perimeter guards, this advance force opened up the main gates, allowing the Spartans in, in force. Quickly going loud, they stormed the outpost, massacring the guards and disabling the defensive weapons, allowing reinforcements to arrive. 
Tapping into the Covenant's encrypted communications, they tracked their fleet movements. Malearnus was rallying his ships, preparing for a devastating attack. Despite sustaining high casualties over the course of the two week campaign his still commanded a significantly large force, large enough to defeat the 16th fleet, should it be brought to bear. Vancamp couldn't allow this. Taking every operational ship he had, he took the fleet to meet Malearnus head on. 
===Operation: CRYSTAL FORTRESS===
Malearnus had returned to the first world he conquered, Ankara, to rebuild his forces. Most of his ships were transitioning to him, and would take their time. However, on the 20th, the 16th Fleet arrived. Finding Malearnus' under strength fleet, Vancamp ordered the charge. Malearnus, suddenly under attack fro the entirety of the UNSC' might in this sector, called the retreat. However, Vancamp wouldn't let him go to easily. Rather than target individual ships, Vancamp's 5 biggest guns fired on Malearnus' flagship at once. In an instant, the ship was gone, reduced to dust and particulates. Suddenly leaderless, the fleet floundered. however, Malearnus' reinforcements had begun to arrive. Recognising that the battle could swing, his subordinates fought back. Expecting them to fail without a leader, Vancamp was surprised by their counter attack. Rather than staying and fighting the growing enemy fleet, Vancamp withdrew to Guinevere. 
Intercepted communications revealed that the Covenant survivors were being brought back into the main blitzkrieg assault. Once this reached UNSC command, Vancamp was ordered to move the bulk of his fleet to support 4th Fleet in facing the main advance. As such, Operation: DEFIANT STAR was considered over. 
Vancamp himself would be left with a skeleton force to resist the numerous pirate bands and raiders that remained. This force was too few in number to take back the dozen or so worlds the Covenant conquered, giving them time to entrench. This worlds would be taken back until November, during a planet hopping campaign.
==Aftermath==
The Covenant took heavy casualties during the campaign, losing their three leaders, and nearly half of their ships and manpower. Those remaining would to be rerouted other war zones, or entrench themselves, fortifying their positions. One the eleven worlds the Covenant still held on to, they dug in, turning former settlements into imposing citadels, the colonists themselves sweating and bleeding to build these for their new masters. Those unfortunate few that couldn't be evacuated suffered the fate of being made slaves, or taken deeper into Remnant territory to be sold on. 
The UNSC took heavy casualties, but ultimately come out victorious. However, their infrastructure in the sector was so badly damaged it'd be years before they returned to a measure of their former strength. The forces were left so drained they could only respond to skirmishes on the new border, and were incapable of taking back their lost worlds. They would stay that way for several more months.