Neutral Zone Incursion The Neutral Zone Incursion was an historical incident in 2266 when a penetrated the Romulan Neutral Zone and destroyed a number of Earth Outpost Station s . The Romulan s used the Neutral Zone as a testbed for a couple of new technologies , such as a cloaking device and a new type of energy weapon , and how these would serve them in a second Earth - Romulan War . It marked the end of a century of isolation on the part of the Romulan Star Empire . ( ) Unknown attacker . On stardate 1709 , the was on patrol along the Romulan Neutral Zone , in Sector Z - 6 , when signals from Outpost 2 ceased . The starship set course for Outpost 4 , the nearest of the outpost s . About an hour later , signals from Outpost 3 also ceased . When the " Enterprise " was a little over eight minutes away from Outpost 4 at maximum warp , the ship received word that the outpost was under attack by an unidentified spacecraft ; contact was subsequently lost . As the " Enterprise " approached the border , Lieutenant Commander Spock was able to take sensor scans of Outposts 2 and 3 ; he determined that both outposts had been totally pulverized , including asteroid s they had been constructed upon . Five minutes out from Outpost 4 , contact between the outpost and the " Enterprise " was reestablished . Commander , the commanding officer of the outpost , reported that Outpost 8 had also been destroyed . Outpost 4 had been hit by an unknown plasma weapon of immense power , that blew through the deflector shield with one shot . Even though the outpost itself was a mile deep within the asteroid , and protected by cast rodinium , the opening attack had caused immense physical damage to the outpost itself . The phaser banks were destroyed and the entire weapon crew killed with just the one hit . After firing , the mysterious starship had vanished , though it remained on tracking sensors . As the " Enterprise " neared Outpost 4 , the mysterious vessel reappeared for a moment , letting loose another plasma torpedo . Contact with the outpost was lost ; Lieutenant Commander Spock reported it had been disintegrated . He theorized that the unknown ship was utilizing an invisibility screen to make scanning difficult , but that it had needed to become momentarily visible because such a high amount of power was required to maintain invisibility that it precluded firing weapons . Pursuit back to the Neutral Zone . The vessel was only visible as a blip on tracking sensors ; this blip , unaware of the " Enterprise " because of the two - way nature of the invisibility screen , changed course to 111 mark 14 , which would take it back through the Neutral Zone to Romulus . The " Enterprise " followed the blip on a parallel course , hoping to make the other ship ( now almost positively identified as Romulan ) think it was nothing more than a sensor reflection . When the Romulan vessel transmitted a code d message to Romulus , the " Enterprise " was momentarily able to tap into the visuals from the ship ' s bridge , obtaining the first - ever visual representation of a Romulan . The Romulans were apparently identical to Vulcan s , which caused " Enterprise " navigator Lieutenant to view Spock with some suspicion . The invisibility system momentarily faltered as the Romulan ship turned , but power was reestablished , and the ship soon returned to its original course . As the " Enterprise " and the Romulan vessel neared the Neutral Zone , " Enterprise " Captain James T . Kirk weighed his options . It was imperative that he stop the Romulan vessel from crossing back into Romulan space , for it would surely mean a second Earth - Romulan War if the Praetor felt the Romulan Star Empire had such a massive advantage . At about twenty - one minutes from crossing into the Neutral Zone , the Romulan vessel suddenly changed course for comet Icarus IV . The plan of the Romulan commander was to obscure the " Enterprise " s sensors in the comet ' s tail so he could swing back and catch the Federation starship off guard . Captain Kirk failed to anticipate this move , however , and swung around to the opposite side of the comet , planning on attacking the Romulan vessel when it became visible as it entered the tail . After the Romulan vessel exited the tail , its crew realized that the " Enterprise " was no longer behind it ; the commander ordered escape maneuver one . Losing track of the Romulan vessel , the " Enterprise " turned hard to starboard . Kirk realized he had underestimated the Romulan commander , and ordered a firing patten laid down at random . The Romulan vessel suffered some minor damage , but the " Enterprise " s phaser control circuit s overloaded and burnt out . As the Romulan ship slowly became visible once more , Captain Kirk realized the danger , and ordered the " Enterprise " into emergency reverse warp , but he was too late ; the Bird - of - Prey launched a plasma torpedo after the " Enterprise " . Even with the " Enterprise " s warp engines on full power , the torpedo was still capable of overtaking the starship . Fortunately for the " Enterprise " , a little less than ten seconds before impact , the torpedo reached the limit of its range and dissipated , causing only minor damage to the ship . The Romulan vessel reengaged its invisibility screen despite its fuel supply draining , and resumed its course on 111 mark 14 ; the " Enterprise " ( its phasers once again operational ) fell back onto its parallel course , going to maximum warp to catch up and hopefully intersect the intruder before it could cross the Neutral Zone border . With less than a minute to go , the " Enterprise " once again launched a number of random phaser barrages , hoping to force the Bird - of - Prey to decloak in order to fire . Though the Romulan ship suffered some minor damage , its commander realized Kirk ' s strategy , however , and ordered all motion cut . Now no longer visible even on the " Enterprise " s tracking sensors , he had the ship ' s debris jettisoned into space , including the body of the only crewman to die thus far . The " Enterprise " detected the debris but realized there was not enough to account for the Romulan vessel . With nothing else to do , the " Enterprise " also cut all power and motion . Each ship ' s captain was trying to outwit the other , seeing who would " blink " first . Cat - and - mouse . After almost ten hours of this waiting game , Lieutenant Commander Spock accidentally activated a device on his panel , while making repairs to the transfer coil of the " Enterprise " s phaser bank s . Detecting the momentary signal , the Romulan ship moved underneath the " Enterprise " to attack it , but Captain Kirk anticipated the move and put his starship into reverse , laying down another random phaser barrage . Rapidly running out of options as his ship ' s limited fuel supply ran low , the Romulan commander once again ordered debris jettisoned in space , this time ordering a nuclear warhead to be added to the mix . As the " Enterprise " approached the debris , it noticed the warhead too late : phasers managed to detonate it a meager 100 meters from the outer hull , sending around twenty crewmembers to sickbay with radiation burns . The " Enterprise " was crippled in the attack , through overloads and circuit burnouts , and only the forward phaser control room was left operational , though it was manned only by Lieutenants Tomlinson and Stiles . Engine power was eventually restored , allowing the ship to move off and make repairs . Captain Kirk declined to do so , hoping that by maintaining the appearance of a tempting target , he could induce the Romulan ship to pull back to the Federation side of the Neutral Zone to attack . The Romulan commander , however , was reluctant to press his advantage , wary of draining his fuel supply , with the ship ' s fuel reserve having been entirely depleted . It was his hope the " Enterprise " would simply move off , allowing his ship to make for home . End game . The Romulan commander was , however , convinced by a subordinate named Decius to attack the " Enterprise " . As the Romulan vessel became visible once more and headed for the " Enterprise " , Kirk gave the order to fire . Unfortunately , a coolant leak had developed in the phaser control room , killing Tomlinson ( the only " Enterprise " fatality in the entire battle ) and knocking out Stiles . Luckily , Spock was in the area and , not affected by the gas eous phaser coolant as much because of his Vulcan physiology , he was able to fire the forward phasers . The Romulan vessel was taken by surprise by the " Enterprise " s sudden barrage , and the ship was crippled beyond hope . Captain Kirk offered to take aboard the surviving crew , but rather than surrender , the Romulan commander performed his final duty and self - destruct ed his ship . In his last transmission , the commander told Kirk , " " I regret that we meet in this way . You and I are of a kind . In a different reality , I could have called you friend . " " Aftermath . With its flagship Bird - of - Prey an apparent failure , the Romulan Star Empire did not follow up on this incursion with a full - scale war , though they did become involved in interstellar politics once again , going so far as to briefly ally with the Klingon Empire in 2268 . The Romulan use of stealth tactics against the Federation set the stage for much of their interaction with the opposing government for the next century and beyond . The incursion revealed two very dangerous technologies at Romulan disposal . The first was their cloaking technology , which allowed them to penetrate the Neutral Zone . The device had a weakness , in that tracking sensors could pick up the ship when in motion , but this was neutralized in later generations of the device . The second technology was the plasma energy weapon . It was capable of outrunning a starship , but its effectiveness decreased with distance . Though Captain Kirk had successfully avoided crossing into the Neutral Zone in his effort to stop the Romulan vessel , Starfleet Command ' s authorization to do so arrived hours after the battle had ended . ( ) Background information . This conflict was invented by " Balance of Terror " writer Paul Schneider . " " I had the concept of this battle in space and this battle over a neutral zone , and I sat there with Gene [ Roddenberry ] and developed it with him , " " he recalled . " " Gene said , ' Take it this way , that way , ' I added my bit and a story came out of it . " " ( " " , p . 34 ) This confrontation between the " Enterprise " and a Romulan Bird - of - Prey was inspired by the World War II submarine movies and , with the " Enterprise " representing a " surface vessel " and the Bird - of - Prey , with its cloaking device , taking the part of a " submarine " . ( " The Star Trek Compendium " , 4th ed . , p . 40 ) The reference book " " ( p . 063 ) speculates that " Run Silent , Run Deep " may have inspired the idea of releasing wreckage and a dead body from a damaged vessel in an attempt to mislead the opposition , whereas " The Enemy Below " influenced the respect the two opposing captains gain for each other over the course of their encounter .