Lieutenant

The Lieutenant or Lou (also dubbed Lou Tenant by some of his subordinates) is the Master's right hand super mutant and the overseer of all work inside the Mariposa Military Base. Lou is a good example of how the Master would want all his mutants to turn out: more intelligent, stronger and overall superior to normal humans.

Background
Think of an urbane and well-educated college professor who has become the very essence of evil incarnate. He is highly intelligent, and is second-in-command to the Master himself. He genuinely believes that the super-mutants and the Unity are the future of the planet, and will do anything to see them succeed. Humans, from his point of view, are less than insects, good only for the Vats, or for being crushed.

The Lieutenant's origins are shrouded in mystery as not much is known about his life prior to his transformation. However, after his transformation into a super mutant, he quickly became the Master's favorite creation due to his high intelligence and devotion to the Master's vision. It may have something to do with him being free from radiation, indicating that he may have come from a Vault. Among other super mutant commanders who led the Master's army, the Lieutenant was appointed to the highest position, being the overseer of the Mariposa Military Base and supreme commander of mutant operations in the surrounding region.

Lou's authority apparently stretches so far that Harry goes through the trouble of dragging the Vault Dweller on a long journey through the wasteland just to show him to Lou and report that he is not a ghoul. Aside from the Master himself, Lou is the best source of information about the Vaults, super mutants, and the general grand plan of Unity. He is a rather sadistic character who thoroughly enjoys torture, as well as arrogantly self-assured concerning the superiority of Super Mutants over normal humans and ghouls, referring to the former as the "next step in human evolution".

During the Vault Dweller's quest to stop the Master and destroy the vats, the Lieutenant resided on the fourth sub-level of the Mariposa Military Base. Here, the Lieutenant would interrogate the Vault Dweller, in hopes of gaining the location of Vault 13. In the end, the Vault Dweller successfully destroyed the Mariposa Military Base and with it the source of the super mutants. During this operation, the Dweller could choose whether or not to visit Lou (thus dooming him to be killed by the explosion), or engage him in battle and kill him.

Abilities
The Lieutenant is noticeably tougher and smarter than standard super mutant soldiers. He has about 250 HP, and is equipped with a gatling laser. He has several cybernetic augmentations (including a bionic eye), and also appears to be wearing metal armor custom-made for his super mutant bulk. During the battle, he is aided by Van Hagan and two heavily armed super mutant commanders (plus, some brain bots that can intervene and strike the Vault Dweller from behind).

Quests

 * Destroy the source of the Mutants: Lou and Van Hagan need to die in order to get the key to the northwest room.

Appearances
The Lieutenant appears only in Fallout as a talking head. He is also mentioned in the Fallout: New Vegas DLC Dead Money by Dog.