What happens when characters come through the rift now?
New arrivals are immediately taken into the old observatory, which now partly serves as the initial quarantine facility (the Center itself being the following — and permanent — stage of quarantine). They are kept there for three days for observation and testing, and given any necessary medical attention. Before they are allowed to leave the observatory and become a resident of the Center, the memory of everything that has transpired since their arrival is erased; they are then sedated and transported to their assigned room.
