PASV-404 is an alternate dimension accessible through a hallway in Sector-91 of the D.A.E. facility, inside is what seems to be the facility but different, the halls never end, if you are lucky you'll find a breakroom, a dorms hallway, or if you're luckier an exit door, the exit leads to a white void with another exit door somewhere in it, going through that door results in spawning back in the lobby of the D.A.E. facility.
