This quest can be started by speaking with Bannon inside the Rivet City Market. He will inform you that he believes Seagrave Holmes is planning to steal his seat in the city council. He then resquests that you to find incriminating evidence on Seagrave Holmes that will put a rest to his stealing of the chair.
You can wander into Seagrave's Room (easy lock, negative Karma) in the Mid-Ship Deck right by the door to the Market District. For no negative Karma loss, you can wait by the door until 7 am, Seagrave should be leaving his room then. Be quick. Once inside find Seagrave's incriminating letter (not marked as owned property, no negative Karma for snatching it) next to the footlocker under the bed. The letter reveals that Seagrave is communicating with the slaver boss Eulogy Jones. Now you can talk with Bannon and Seagrave Holmes.
Seagrave claims that the message makes it clear that he is not going to cooperate with the slavers and that you should inform Lana Danvers that Bannon is trying to blackmail him. Bannon will tell you to report this evidence to Lana Danvers, but not to tell her that it is he who sent you on the task to find evidence against Seagrave.
- You can find Lana Danvers at the third level of the tower. Just go up the stairwell to the top, and enter the door that says bridge tower. At this point, you are presented with the choice to support either Bannon or Holmes.
- Lana Danvers can also be found in the marketplace after 9:00 pm. Be warned, the market closes after dark. Some characters in the Marketplace may tell you to leave or say "You shouldn't be here!". Stay too long and nearby non-player characters may turn hostile. It is recommended that you have a quick exchange with Danvers and leave before this happens.
- Choosing which party to support is a tactical choice, since Bannon rewards the player with a deathclaw gauntlet schematic and sells the player apparel at a discount whereas Holmes gives no instant reward, yet has more material to make use of the 10% discount with.