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].

AntAgonizer's Lair
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 button on the wall lowers stair case to a cave. Continue through the cave, killing a few ants and you'll soon reach her lair.

Alternatively, you can sneak in the back entrance, a pipe to the west of the entrance at the top of a mountain of rocks. This route bypasses all of the ants in the tunnels.

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. If you choose to help her, you will be awarded with the Ant's Sting, which is a knife that poisons an enemy for 4 damage per second for 10 seconds.

If you have the Lady Killer perk, you get a dialogue option that allows you to help her see the error of her ways. Selecting it will make her stop being the AntAgonizer and leave, giving you her funny outfit. Be sure to keep it if you plan to also convince the Mechinist to end his "career": he will want to destroy it.

If you are wearing the Mechanist's costume, she will attack you.

Mechanist's Lair
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. Otherwise, the facility is broken up into four sections: Office (left of Entrance), two Maintenance areas (Sector A and B, which are connected by a control room on the upper level) and the Forge (where the Mechanist is hiding). Sector B is closest to the entrance (metal door past the elevator), and the Forge entrance is on the upper level of Sector A.

The security terminal for Sector B is in the control room on the upper level, which allows you to disable the automatic turrets and security robots (i.e Mr. Gutsy). The emergency security terminal for Sector A is located in a small control room near the back of the bay, close to the Forge entrance (upper level). From this terminal you can disable the automatic turrets in this room, as well as emit an Emergency Pulse Explosion that will destroy any active robots in this sector.

Once you enter the forge, activate the coffee maker to reveal the Mechanist's lair. While you're here, there's a huge amount of scrap metal and energy cells to be found in the facility (including a 'Nikola Tesla and You' book in Sector A).

Convincing the Mechanist to end his superhero career and leave the town alone will grant you his suit, and positive karma. Telling him you have defeated the AntAgonist but encouraging him to continue his superhero ways grants you "Positrons Gaze," and negative karma. Protectron's Gaze is a laser pistol that fires bursts of laser fire like a shotgun.

Completion
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 200 more caps; 400 even if you didn't succeed in the speech attempt when given the quest, or 600 if you did.

Alternatively, you may kill one or both immediately upon entering town (they're invincible for a short time while talking, but can be harmed soon after). Doing this grants you whatever that one had on him/her, as well as 400 caps from Uncle Roe (without ever needing a Speech check).