Murphy's Bombing Run

Murphy's Bombing Run is an unmarked and repeatable quest in Fallout 3.

Detailed walkthrough
Murphy is a ghoul scientist, stationed just inside Northwest Seneca Station, who is working on an improved version of the drug Jet, which he named Ultrajet. However, he wants the Lone Wanderer's help with finding one of the ingredients, Sugar Bombs. For every box of Sugar Bombs that they bring him, he will pay them 15 caps, which can be increased to 30 caps by passing a Speech check when first talking about the quest. He will then sell one Ultrajet for every eight boxes of Sugar Bombs brought to him

Bugs
After speaking to Murphy for the first time, giving him any boxes of Sugar Bombs will result in one not getting paid. Leaving the area and then returning will fix this problem.