Bill's letter is a paper note in Fallout 4.
Location[]
The note can be taken from Cedric Hopton if he is killed at the Third Rail.
Transcript[]
My name is Bill Sutton and I'm the foreman at Warwick Homestead. We got a little synth problem here and I'm looking for a hired gun to take care of it.
The man you're after is called Roger Warwick, except he ain't actually a man at all, he's a damn synth spy. Those institute bastards grabbed the real Roger and they put this faker in his place. Well, they might of fooled Roger's wife and kids, but they ain't fooled me.
Take these caps as half your fee. I'll give you another 500 when the deed is done, but I don't want any of this to connect back to me. I plan to take over the farm when Roger's gone and I need it to look legitamit .
Don't take your time, either. I want this done soon, or I'm going to take matters in to my own hand and then you missed your chance at a even bigger haul then what you already got.