You'll eventually reach a fallen Nightkin and a Chewed Stealthboy on his body. Take Lily to the Charleston Cave to the north and fight through the Nightstalkers. You can also use this to recruit Lily as a companion. Henry in the lodge and he'll give you info about the insanity troubling the Nightkin. For the latter option, talk to Marcus and gain the caps to pay off the NCR.
More evil approaches include killing the NCR outright, or bribing them with the towns funds. You'll need to construct your look and distribute your skills. Your life has been saved by Doc Mitchell. Complete G.I.Blues and start Nothin' But a Hound Dog Rex: The King's cyber dog in Freeside.Repair him with science skill, repair, or gain the needed parts
Make sure to have non-evil fame with the Brother hood of Steel or NCR