Mr. Burke

Mr. Burke is the right-hand man of hotelier Allistair Tenpenny in Fallout 3 who can be encountered just as the Lone Wanderer escapes Vault 101. He is initially found in Megaton where he presents an explosive proposition to the player.

The Power of the Atom
In the side-quest "The Power of the Atom", Mr. Burke resides in Moriarty's Saloon where he'll address the Lone Wanderer with his proposition to detonate the bomb in the center of Megaton at the behest of his employer Tenpenny. Should the Lone Wanderer accept the fusion pulse charge needed to detonate the bomb, Burke will go to Tenpenny Tower to await the Lone Wanderer's arrival when the bomb is rearmed. If his offer is refused, Burke will go to Tenpenny Tower but this will result in hit-men attacks afterwards.

At Tenpenny Tower after rearming the bomb, the Lone Wanderer can rendezvous with Burke who will give the Lone Wanderer the honor of pressing the button (which will result in massive Karma loss). He expresses a sadistic pleasure with the knowledge of the bomb's rearming and marvels at the sight of the explosion.

Other Outcomes
It is possible for the Lone Wanderer to accept the fusion pulse charge and then report Burke to Megaton's Sheriff Lucas Simms. If done, Simms will attempt to arrest Burke but be shot in the back when he tries to lead Burke out of Moriarty's Saloon. The Lone Wanderer can kill or disarm Burke to prevent this from happening. The Lone Wanderer will gain Karma for killing Burke.

If the Lone Wanderer accepts the offer to rearm the bomb and aids the ghoul Roy Phillips in the takeover of Tenpenny Tower (thus resulting in the death of Tenpenny), Burke will still rendezvous at the Tower, stating that he has unfinished business and will see through to the detonation of the bomb. From there, the Lone Wanderer can still press the button and accept the reward for rearming the bomb. If the Lone Wanderer had aided Phillips during the takeover before encountering Burke, he will become Phillips' right-hand man.

Trivia

 * Burke can be seduced using the Black Widow perk.
 * Burke appears in the form of "Mister Break" during the add-on Point Lookout, a figure who appears in a hallucination experienced by the player after ingesting pungas seeds.
 * Burke and the option to detonate the Megaton bomb are both omitted from the Japanese version of Fallout 3 for cultural reasons.