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.

Walkthrough
This quest is given to you by:
 * The Sheriff Lucas Simms, wants you to disarm the nuclear bomb in the middle of Megaton. Lucas will at first offer you 100 caps, but you can use Speech to raise the bounty to a total of 500 caps.
 * Mister Burke who wants you to help him detonate it, 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. You can use Speech 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 you activate the bomb (considering you have 25 Explosives Skill), and disarm it, the quest is started. This is extremely useful if Lucas Simms was killed before you started the quest, since you can get the reward from his son.

Rig Megaton's atomic bomb to explode
To do it, you have to put a fusion pulse charge, given to you by Burke, inside the bomb. Your Explosives skill must be 25 or higher for you to attempt it; Mentats can be used to boost your statistic.

In the Japanese version of Fallout 3, Mister Burke does not appear and the player cannot get the Fusion Pulse Charge. The only options are to disarm the nuke or ignore it. This option was removed because the Japanese found it offensive because of the nuclear attacks on Hiroshima and Nagasaki in 1945 (World War II). The name of the weapon "Fat Man" was also changed, due to Fat Man being the name of the nuclear weapon which was deployed on Nagasaki.

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

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

If you help Roy Phillips take over Tenpenny Tower in the Tenpenny Tower quest prior to completing Power of the Atom, you may still complete Power of the Atom. When you return to the top floor penthouse, you 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 you to disarm Megaton's bomb. Your Explosives skill must be at least 25 to attempt this. Taking some Mentats can temporarily increase it to the necessary level, unless it was very low to begin with. If you are successful you get a cash reward and the keys to your own Megaton house. The cash reward is usually 100 caps, but with a successful use of your speech skill on Lucas (before you actually disarm the bomb) you can talk him into a reward of 500 caps (like you can Burke into 1000 instead of 500 caps). If you declined payment, you will typically gain 200 Karma instead, though if you disarm the bomb right away, without letting Simms welcome you to Megaton, he will give you the 100 caps.

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

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

Optional: Leo Stahl's Drug Stash
If your Explosives skill is insufficient (below 25), you will be unable to rig or disarm the Megaton bomb. If your Perception is at least 5 and/or your Explosives skill is at least 20, you can raise it sufficiently 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 your Karma is low enough (if you got the fusion pulse charge, mention it and Simms will take it away and proceed). Take care not to "cry wolf," so to speak, because he will not believe you if you rescind your initial warning. Lucas Simms will tell you to follow after informing you that you're about to see Wasteland justice first hand. Simms will attempt to arrest him. 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 him 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 you wish to listen to the dialogue between Burke and Simms, you 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 police baton) 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 1 shot (either in or out of V.A.T.S.) to kill him, Mister Burke may still kill Simms. You can try to shoot the silenced 10mm out of Burke's hand instead of killing him. This will give the sheriff time to respond and give you more wiggle room in dealing with Burke since he will now be unarmed. If you kill Burke before he kills Lucas, the sheriff will thank you afterward. The same response is given whether or not you waited until Burke 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 to you. During this time you can take out your own weapon and kill Burke.

If you don't act fast, Simms is killed. Afterward, Mister Burke gives you a threat and disappears. If you kill Burke before he disappears, he says his friends will avenge him. If you let Burke kill Lucas Simms, then you kill Burke, you can loot both bodies. This will get you a silenced 10mm pistol and a Chinese assault rifle, plus some caps and ammunition. If Lucas Simms dies you can still complete this quest by talking with his son, Harden Simms, after disarming the bomb.

Neither option will result in a negative reactions 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 accidentally hits Simms, the town may become hostile and retaliate.

Seducing Mr. Burke
If you play as a female character and have the Black Widow perk you can seduce Burke and get him to spare Megaton. He will then leave the city, with the promise of sending for you later; he will even send you love letters, which can be picked up at Moriarty's Saloon. Another possibility is persuading him to give you 1000 caps upon detonation of the bomb, as opposed to the 500 you would normally get.

Using the Black Widow perk to seduce Burke still results in him putting a hit out on you if you choose to disarm the bomb later.

If you disarmed the bomb

 * 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 you disarmed the bomb for free
 * A Contract for Extermination will be set out on you by Mister Burke or Allistair Tenpenny; Talon Company will start hunting you.

If you destroyed Megaton

 * Bottle caps
 * 1000 - If Speech was successful at start of quest, or if the Black Widow perk was taken and unique dialog 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 you. You might also be ambushed by angry former Megaton citizens.