Just gotta do Unify route and get the hidden will.
Files from the first game are in there because there's a gallery in the Lab, its the little console on the left that's jutting out from the wall
I would hazard a guess that you take the second key to the basement but help is welcome.
So just to be clear, keys only really matter in the Unify route. Second key goes to the grave after the Greenhouse mini game, Billy drops a hint about it
