You Gotta Shoot 'Em in the Head

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

Awhile ago, Allistar Tenpenny hired five mercenaries, Crowley, Tera, Dave, Strayer(Who has since died) and Dukov. They were hired to find a rare gun for Tenpenny. Tera died in the fort and Crowley supposedly bit the dust. After feral ghouls got Tera, Dukov realized he would get more of the commission. So he later locked up Crowley in a room with feral ghouls, which never harmed him. The three remaining men finished the mission with Dave and Strayer being very leery and cautious.

Objectives and walkthrough
Mister Crowley, a resident of Underworld tasks you with finding and killing Dave from the republic of Dave, Ted Strayer, Dukov, and Allistair Tenpenny. He asks you to do this because they are Ghoul bigots. If you manage to successfully persuade Ahzrukhal, you can find out through a short chat with Mister Crowley that what he really wants is the keys each person has. instead or 100 caps for each headshot, he will give you 100 caps for each key you bring him, also with an added bonus. however he still wants you to kill Allistair Tenpenny.

Getting the Keys
You can pay, persuade or kill Dukov for his key.

Strayer's son is now in possesion of his father's key, which you can either persuade him to give you, threaten him or pay him for. Or kill him.

To get Dave's key you can kill him, steal it or persuade him, just don't mention Chrowley would like for you to kill him. Go with the Wasteland Ambassador Route, which needs very little speech skill, to get the key.

Choices
Now you have a few Choices, you can use the keys to go to Fort Constanstine to get the T-51b Power Armor or return the keys to Crowley. Of course if Chrowley already has the keys or you just gave him the keys you can steal them back or kill him for them.

Getting the T-51b Power Armor
First off you have to reach the fort, in the top east part of your map, near Raven Rock. If you travel from Raven Rock, be prepared to fight Enclave troops, Yao Guai and some treacherous terrain. Closer to the fort you encounter some Brotherhood of Steel Outcasts fighting protectrons and Mister Gutsys