I subscribe to the "immune Tanya" theory. Maybe she was bitten by the slow turning guinea pig they had at the Colony, and that would explain also her interest in studying the creatures and her panic when she's about to be exposed.
I also enjoyed Chinwe's lines about the oxygen: "You have 25 minutes to go in and 25 to get out".
Might as well said "You have one episode to go in, cliffhanger, then another episode to get out."