Treachery at Port Maw - Treachery: The situation in the Port Maw System was one of extreme and ruthless order holding back a tide of chaos. The shell of the great artificial planetoid on which the vast Imperial naval base and void-forges had been built was choked by a swarm of vessels, both mighty and small, from a score of battleships girding themselves for war, to dozens of cruiser squadrons, countless hundreds of Escorts and thousands of servitor-drone tenders, victuallers and supply ships, troop transports and orbital lighters -- all about their own business as the entire star system stood on a state of high alert. In grim alliance, reinforcing fleets had come from the east, dark bronze warships bearing the fiery lantern-sigil of the Agathean Domain, one of the most isolated of all of the Imperium's clusters of human civilisation, lean pirate-killers from the Cerada Nebula and a trinity of huge storm-grey war-arks from the Mechanicum Forge World of Cyclothrathe, void-automata scuttling across their hulls like macabre insects.Into this morass of vessels, before the border fell silent, had also come the refugees from the storm. Some had been mercantile vessels, other great livestock conveyors or ore transports, fleeing from a dozen different star systems under threat or under attack, and others were warships, the ragged survivors of the battles in the Cyclops Cluster. A handful had fled from as far afield as the murderous void battles at Istvaan, but of these no Space Marine vessels remained long at anchor. Of this flotsam of war, most had been mauled by the enemy or driven past any safe operational ability in the desperate flight to reach safety, and all required aid and assistance of some kind. Some even had arrived in such a parlous state that they had to be scuttled or set to drift at the system's edge so they posed no danger to the vortex of ships that swirled around the port station.This hurricane of vessels, with its complexity and ever-shifting maze of hazards, was far too great a burden than any merely human mind could bear, and control of the vast armada was channelled through Port Maw's Mechanicum Astra Control Panopticon. This powerful broadcast tower, ten kilometres high, jutted spike-like from Port Maw's southern pole. From here fleet orders and beacon signals were relayed, navigational co-ordinates checked and rectified, and centrally controlled Cogitator-maintained data directly fed into the helms of the ships under Port Maw's watch, so as to swiftly reorganise their patterns and avoid collision. This system could, of course, be overridden by the ships themselves, but still represented a terrible vulnerability and so the Panopticon's control frequencies had been proofed against treachery by a complete replacement of cyphers and encryption-djinn following the reveal, first of the Warmaster Horus' treachery, and then changed again with panicked haste after the double blow of yet more betrayal at Istvaan V.This had been of even greater concern as a significant portion of both the Raven Guard's and the Iron Warriors' fleets had made layover for resupply at Port Maw on their way to what would become the Drop Site Massacre, and both had been fully updated on the Port's codes and deployment schedules. All of this was deemed compromised and once again swiftly replaced wholesale and, due to this, the Port Maw Void Augury and geas-override systems were believed by the Armada Command to still be impregnable against outside influence. Indeed, perhaps they would have proved so, except that the spider at the heart of this vast web, the Archmagos Leit Mercuric, Cyber-Ordinator of Port Maw, was already secretly sworn to Horus.