Presper infected himself, Coleridge, and a handful of loyal soldiers with the New Plague so they would be taken into Tibbets Prison. Once there, the rest of Presper's men, who were not infected, would stage an attack on the prison which would allow everyone to escape. This event would start a countdown for the missile launch onboard Ballistic Orbital Missile Base 001. ODYSSEUS would assess the viral spread, try to gather up the escaped prisoners, and, once 90% of the prisoners had been retrieved, launch nuclear missiles to "clean & prevent" any further infection.
Coleridge doesn't believe in killing anyone who isn't threatening him, and believes solely in his holy crusade to take back the New California Republic (NCR) from Governor Dodge. He is also suspected of being responsible for the attack on the New California Republic Congress.
Successfully knock out or kill the engineer without alerting Presper and his men, if the player has successfully sneaked past the security bots on the central hub, (which in turn does not set off the internal alarms) then the player can try to sneak up on the engineer who is busy fiddling with a computer on the southwest side of the engineering room. If the engineer raises the alarm, Coleridge and his boys will storm in, guns a blazing.
Convince Coleridge that Presper deceived them, convincing Coleridge that Presper deceived them about the New Plague and instead gave him and his men a virus that would eventually kill Coleridge and his NCR soldiers. This news will get Coleridge to turn on Presper. It also clears the way for the player to re-target the missiles, if he wants, without opposition.
When the Prisoner fights the security bots outside of airlock 3, instead of sneaking around or disabling them, Coleridge and the NCR guards will be waiting for him. Coleridge will "politely" request that the Prisoner holster his weapon (if drawn) and come with him to meet their commander, Dr. Presper, in the command control room.
As the head of the NCR soldiers aboard the station, the Prisoner may have to kill Coleridge to stop Dr. Presper and the missile launches.
Coleridge has not appeared nor is he mentioned in any published game. He was to appear only in Van Buren, the canceled Fallout 3 by Black Isle Studios. It is not certain if he will appear in any future Fallout game.