1. Turn on power
2. Go to the upstairs of power room, there will be 2 red buttons one of the left side and one on the right
ONCE BOTH ARE ACTIVATED YOU WILL GET TELEPORTED TO THE AETHER
3. Once in aether you will be trapped in power room and must kill zombies until you get teleported back

After you are teleported back a gate will open and a small walkway will open in the top of the power room, Jump in the big orb and you will be teleported to the PAP room