Brian Virgil

Virgil is living initially in the rocky cave and is part of the quest to get into The Institute.

Interactions with the player character
After joining the Institute, Virgil will ask you to get an experimental serum that he claims will make him a human again, but isn't sure if it exists or not. If the player agrees, they will have to go to the FEV labs in the Institute to retrieve the serum. After getting the serum, the player has two options: If the player gives Virgil the serum and waits for a week or two, they can go back and see that Virgil is now a normal human. He almost acts like it's no big deal, when it really is; he just found a cure to FEV. Albeit only one strain, and that it takes a week for it to take effect, it's the strain used to create Commonwealth Super Mutants and can possibly have the effects bolstered to take less than two minutes.
 * They can simply give Virgil the serum, and certain companions will act differently to this choice. For example, Piper would like it if you did, but Danse won't like it at all.
 * They can also lie to Virgil through a speech check, claiming that it wasn't there, which will prompt him to commit suicide.

Effects of player's actions
If the Sole Survivor has found the serum in The Institute but lies about it upon returning to Virgil, he can be talked into killing himself.

Appearances
Virgil appears only in Fallout 4.