The Power of the Atom

The Power of the Atom is a Fallout 3 quest. It is also a PS3 trophy, and an Xbox 360 and PC achievement.

In the quest, the Lone Wanderer is given the choice of disarming or detonating an atomic bomb, thus deciding the fate of a town and its inhabitants. The quest is considered to be one of the best in Fallout 3, and has been described as "game-defining."

Detailed walkthrough
This quest is given to you by:
 * The Sheriff Lucas Simms, wants the Lone Wanderer to disarm the nuclear bomb in the middle of Megaton. Lucas will at first offer 100 caps, but Speech can be used to raise the bounty to a total of 500 caps.
 * Mister Burke who wants the bomb detonated, as his employer, Allistair Tenpenny, considers Megaton a blight on the landscape of the Capital Wasteland; Burke can be found in Moriarty's Saloon in Megaton, casually sitting in the corner. A Speech check can be used for a chance to increase the bounty for detonating the bomb by 500 (total of 1,000) or the Black Widow perk (character must be female) to guarantee a raise of 500 caps.
 * If the player character activates the bomb (25 Explosives Skill), and disarms it, the quest is started. This is extremely useful if Lucas Simms was killed before the quest is started, since one can get the reward from his son instead.

Rig Megaton's atomic bomb to explode
To rig the bomb, the Lone Wanderer has to place a fusion pulse charge, given to them by Burke, inside the bomb. This requires an Explosives skill of 25 or higher for a successful attempt. Mentats and/or the Raider blastmaster helmet can be used to boost the Explosives skill if the player character is within seven points of the required threshold.

In the Japanese version of Fallout 3, Mister Burke does not appear and the player character cannot get the fusion pulse charge. The only options are to disarm the nuke or ignore it.

Report to Mister Burke in Tenpenny Tower
After rigging the bomb, meet Burke at Tenpenny Tower, which is southwest of Megaton near the RobCo facility. There, the explosion can be observed from a safe distance together with Burke and Tenpenny.

Mister Burke will give the player character the 'privilege' to push the button to detonate the bomb. Doing so instantly lowers the player character's Karma by 1000 points. If Karma before detonation was 0 or negative, a change of -1000 Karma will instantly lead to the lowest possible Karma in the game.

If helping Roy Phillips take over Tenpenny Tower in the Tenpenny Tower quest prior to completing Power of the Atom, the player character may still complete Power of the Atom. When returning to the top floor penthouse, the player character will stumble onto Roy Phillips and Mister Burke having a conversation. Roy is intimidated by Mister Burke and the fact that he made his way to the top floor. Roy agrees with Burke on the matter of blowing up Megaton and also states that he could use a man like Burke, thus Burke begins a new partnership with Roy Phillips.

Disarm Megaton's atomic bomb
Lucas Simms wants the Lone Wanderer to disarm Megaton's bomb. The player character's Explosives skill must be at least 25 to attempt this. Taking some Mentats and/or equipping the Raider blastmaster helmet can temporarily increase it to the necessary level, unless it was very low to begin with. If successful, the player character will get a cash reward and the keys to a personal Megaton house. The cash reward is usually 100 caps, but with a successful use of the Speech skill on Lucas (before actually disarming the bomb) the reward can be upped to 500 caps. If the player character declines payment, they will typically gain 200 Karma instead. If the bomb is disarmed before speaking to Simms, he will give the player character 100 caps if it is brought up in further conversation.

Mister Burke will leave Megaton after defusing the bomb. As a result of disarming the bomb, Talon Company mercenaries hired by Mister Burke will randomly appear in an attempt to kill the Lone Wanderer.

Optional: Deal with Mister Burke
This section of the quest is optional. The player character can kill Burke after speaking to him, without talking to Simms first. Killing him will result in good Karma and avoid risking Simms possibly getting killed. The player character can also accept the quest to blow up Megaton, and then kill Mister Burke, without penalty.

Optional: Leo Stahl's drug stash
If the Explosives skill is insufficient (below 25), the player character will be unable to rig or disarm the Megaton bomb. If Perception is at least 5 and/or the Explosives skill is at least 20, it can be sufficiently raised by consuming Mentats. One nearby source of Mentats is Leo Stahl's drug cache, which is hidden inside a desk within the water processing plant. One can gain access via the Leo's Drug Habit quest, by picking the lock on the desk (very hard), or by speaking to Doc Church.

Report Mister Burke to Lucas Simms
After speaking to Burke, a new dialogue option will become available when speaking with Lucas Simms, which can result in him confronting Burke about the plot to destroy Megaton, as long as one's Karma is low enough (if the fusion pulse charge has already been acquired, mention it, and Simms will take it away and proceed). Take care not to "cry wolf," so to speak, because he will not believe the player character if the initial warning is rescinded. Lucas Simms will tell the Lone Wanderer to follow, after informing them that they're about to see "Wasteland justice" first hand. Simms will then attempt to arrest Burke. Burke will deny the allegations, but will eventually agree to be detained and suggest that Lucas "Lead the way." As Simms turns to lead Burke to jail, Burke pulls a silenced 10mm pistol on Simms and kills him. (It seems that, if Simms manages to exit the room before Burke takes the shot, the latter will just shoot at nothing in particular. Lucas Simms can then be found dead, outside the saloon.)

Most of the time, saving Simms would involve killing Burke before he draws his weapon, or even before Simms confronts him (which will still yield the same amount of positive Karma). However, if one wishes to listen to the dialogue between Burke and Simms, one can still prevent Simms from dying by killing Burke as soon as he pulls out his gun. To do this, have a high powered gun (scoped .44 Magnum, sniper rifle, combat shotgun or possibly even a decent melee weapon like a baseball bat) drawn and ready while the two are having their conversation, and as soon as Mister Burke draws his gun, blast him (preferably a headshot to ensure an instant kill) manually or with V.A.T.S. If it takes more than one shot (either in or out of V.A.T.S.) to kill him, Mister Burke may still kill Simms. It is possible to shoot the silenced 10mm out of Burke's hand instead of killing him. This will give the sheriff time to respond and give the player character more wiggle room in dealing with Burke, since he will now be unarmed. If Burke is killed before he kills Lucas, the sheriff will thank the player character afterward. The same response is given whether or not Burke is killed before or after he drew his weapon. It is also possible to immediately press the action button to talk to Burke just before he attempts to kill Lucas after Lucas tells Burke to follow him and turns his back. He will be irritated but will pause to speak. During this time the player character can take out their own weapon and kill Burke.

If one doesn't act fast, Simms is killed. Afterward, Mister Burke will threaten the Lone Wanderer and disappear. If Burke is killed before he disappears, he says his friends will avenge him. If Burke kills Lucas Simms and then the player character kills Burke, both bodies can be looted. This will net a silenced 10mm pistol and a Chinese assault rifle, plus some caps and ammunition. If Lucas Simms dies, one can still complete this quest by talking with his son, Harden Simms, after disarming the bomb.

Neither option will result in a negative reaction from the townspeople, though they may comment "better him (or her) than me" if they see it take place. If in any way the player character accidentally hits Simms, the town may become hostile and retaliate.

Seducing Mister Burke
If playing as a female character and have the Black Widow perk, Burke can be seduced and persuaded to spare Megaton. He will then leave the city, with the promise of sending for the player character later; he will even send a love letters, which can be picked up at Moriarty's Saloon. Another possibility is persuading him to give the Lone Wanderer 1,000 caps upon detonation of the bomb, as opposed to the 500 normally given.

Using the Black Widow perk to seduce Burke still results in him putting a hit out on the Lone Wanderer if the bomb is disarmed later.

If the bomb is disarmed

 * Bottle caps
 * 500 - If Speech was successful at start of quest
 * 100 - If accepted offer, Speech failed, or wasn't employed at start of quest
 * My Megaton house key
 * Deed: My Megaton house
 * 300 XP
 * Karma [+200]: If the bomb is disarmed for free
 * A contract for extermination will be put out by Mister Burke or Allistair Tenpenny and Talon Company will start hunting the player character.

If Megaton is destroyed

 * Bottle caps
 * 1000 - If Speech was successful at start of quest, or if the Black Widow perk was taken and unique dialogue is chosen
 * 500 - If accepted offer, or Speech failed
 * My Tenpenny Tower suite key
 * Deed: Tenpenny Tower suite
 * 300 XP
 * Karma [-1,000]: If Megaton is destroyed
 * With a lot of negative Karma, the Regulators will start hunting the player character. It is also possible to be ambushed by angry former Megaton citizens.

Behind the scenes

 * The coordinates displayed on the remote detonator at Tenpenny Tower (-01,-07), are the actual coordinates of the game cell which contains the bomb.
 * In the Japanese version of the game, Mr. Burke will not be present in the game, not allowing the player character to rig the bomb to explode. This is due to the memory of the Atomic bombings of Hiroshima and Nagasaki still remaining strong in the country.