Keene is an influential nightkin in Jacobstown who has a pull on other nightkin, attracting others to the town and keeping the ones already there from leaving. Marcus claims that Keene is smart, charismatic and more sane than most other nightkin, but also very impatient, speaking with him will reveal just how impatient, not to mention irritable, he really is. Eventually, his impatience towards Doctor Henry's cure for nightkin schizophrenia causes him to attempt to take the Stealth Boy Mk. II by force, so that the nightkin can see how it works and upgrade all Stealth Boys they find as they roam the Mojave doing unjust deeds.
Guess Who I Saw Today: After discovering the source of the nightstalker mutations and testing the unstable Stealth Boy Mk. II on Lily for Dr. Henry, he and two of his nightkin followers arrive to take the Stealth Boy Mk. II so they can leave Jacobstown, assimilate the Mk. II and upgrade any Stealth Boys they find. Keene can be dissuaded and the situation solved peacefully with a speech skill of 80. Otherwise, he will attack and you must kill him. Marcus claims it was probably inevitable and that it will be hard to attract more nightkin to Jacobstown, and even harder to keep nightkin already there from leaving. It is also possible to give Keene the Mk. II schematics, and he and his gang will then leave. This has a significant post-game impact which is explained in the Fallout: New Vegas endings.