Under the Mountain is a note in Outlast.

It is acquired by filming the first room in the Underground Lab.


"Fuck. Fuck, fuck, fuck.
Whoever finds my corpse- trust no one and tell everyone. I am not crazy. I know, I know, only crazy people say that. But I am as sane as this world allows, with a camera full of evidence. Don't call it a gospel. Call it a mockery of reason, let the world know it is Murkoff's fault. Bury these bastards with my mutilated dead body."