The Superhuman Gambit

 is a Fallout 3 quest. It is also an Xbox 360 and PC achievement.

Objectives and walkthrough
The town of Canterbury Commons has became the battleground of two self-claimed "superheroes" - the AntAgonizer and the Mechanist. Its inhabitants are not very happy about it and want you to help them get rid of them.

Once you acquire this quest, speak to Derek Pacion. He gives you the best info on where to find them. Apartently the AntAgonizer lives in a cave north of town and the Mechanist lives south of town in a old robot factory [Both spots marked on your map]. With Child at Heart perk you can ask Derek for their weaknesses. The Mechanist doesn't harm innocent and the ants are weak, except for royal guard [my guess royal guard is soldier ants].

If you decide to take out the AntAgonizer, you head to her cave northish of town. Inside you continue forward, watching out for frag mines. [Taking right path takes you to random equipment and a combat shotgun trap]. Down the stairs and quick right leads you to an empty room. A bottom on the wall lowers stair case to a cave. Continue through the cave, killing a few ants and you'll soon reach her lair. Inside, there are no ants to fight, just the AntAgonizer. Speaking with her you can either decide to kill her, or help her destory the Mechanist. Lady Killer: You can help her see the error of her ways and she will stop being the AntAgonzier and leave, giving you her funny outfit.

If you decide to visit the Mechanist, who resides in the "Robot Repair Shop" in the southern part of the city, you can attack him, have him join you against the AntAgonizer, or talk him out of the whole thing.

To reach the Mechanist's Lair without having to fight through his robotic security, you can repair the elevator near the entrance, bypassing the heavily guarded stairs, but only if your repair skill is high enough.

Once you defeat either return to Uncle Roe to receive 200 caps. [400 if you got successful speech].

Should you succeed in talking both of them into ending their "careers" (or just leaving Canterbury Commons) you will receive 400 caps even if you didn't succeed in the speech attempt when given the quest.