yeah i'm just gonna... yeah.
[ he's walking through with his customary stack of books, and he pauses to observe the activity. after a beat ]
Might I suggest a few indices? Perhaps one on the warden currently in charge, one on the unique worlds to the best of your ability, and one on the inmates themselves?
[ for deciphering patterns, you see. ]
You may also wish to consult the Defense Force; [ mild amusement here ] they continuously monitor life signs from inmates in the dome and are aware of new arrivals as well as missing persons.