Well the door's not really important. This whole thing will be over soon enough no matter what happens, that Malnosso guy even gave us heads up that he was going to screw with us.

So the more important question is how to tell if we're alive or dead if we can't actually die. Or, for that matter, if we're actually us and not some kind of creepy clone version while the real us are in laboratories somewhere. [ Like in The Matrix. ]