Murphy (Fallout 3)

Murphy is a ghoul scientist stationed just inside Northwest Seneca Station. He has an assistant named Barrett, who acts mostly as a bodyguard.

Unmarked quest: Murphy's Bombing Run
Murphy is working on an improved version of the drug Jet, known as Ultrajet. However, he needs your help with one of the ingredients: Sugar Bombs. For every box of sugar bombs that you bring him he will pay you a 15 caps (30 if you pass a Speech check). You can then purchase Ultrajet from him.

The first time Murphy offers you a look at his inventory, which includes Ultrajet and a handful of other drugs, he will have zero caps. Once you purchase Ultrajet from Murphy, you can sell him any items in your own inventory to get some or all of the caps back. However, any items you sell him will automatically disappear from his inventory, so do not sell him anything important.

Appearances
Murphy appears only in Fallout 3.

Note
Murphy and his assistant will go hostile when they see Fawkes (happened twice, after I reloaded the autosave into the subway tunnel). Fawkes will dispose of them easily, so if you want to kill them without a Karma hit, this is a simple way to do it, but otherwise, tell Fawkes to wait outside.