The Amazing Aqua Cura!

 is a Fallout 3 quest that is added to the game in the Broken Steel downloadable content pack.

Walkthrough
This quest can be started by hacking Scribe Bigsley's computer and looking through the logs, or by talking to Griffon himself in the Museum of History. Griffon, a ghoul outside of the Underworld, is selling Aqua Cura that is radiated, but he says it isn't and it will cure being a ghoul. If you keep talking to him you will eventually need to talk to Scribe Bigsley. He will tell you that Griffon's operation is in the Museum Authority Building. When you first enter the building go to the very back and find a stair way going downstairs. When you go downstairs take a right into a big room with barrels and tubs. In between 2 tubs on a coffee table are 2 Dirty Water, a Nuka-Cola, a Clipboard, and a Holotape. The holotape tells you that Griffon's Ghoul Guards dump the Aqua Pura into the tubs and sinks, making them radiated. When you go confront Griffon you have the options of: blackmailing him for 300 caps, or caps every week; telling him to confess to his audience that his Aqua Cura is radiated, or you tell them yourself; or telling him you won't expose him so long as he sells real Aqua Pura from that point on.

Forcing Griffon to confess
If you force Griffon to confess about the true nature of Aqua Cura, the crowd will turn hostile against him. Griffon will attempt to defend himself, but ultimately runs away and hides in one of the bathrooms at the entrance of the Museum of History. The crowd will follow him into the bathroom where Griffon will make a final stand but is eventually killed by the angry mob. Griffon's body can then be looted for ammo, 200 caps, a Chinese Pistol, a Dirty Pre-War Businesswear, and a Wig.

Selling the real Aqua Pura
If you come back one week later as instructed, and speak with Griffon he tells you that business has been concluded and get the crowd to cheer for you, or something of that nature. If you kill him the mob doesn't turn hostile and you can loot him for 600 Caps, a wig, a Chinese Pistol, and a Dirty Pre-War Businesswear.