Sometimes people disappear, but....apparently that just means they are lost within the dimensional stabilizer.
[...... she doesn't know what to believe in regards to that any more, not after what they've all recently learned, what people say they saw in that strange building...]
Usually they are brought back, at some point, but...not always with their memories in tact.
[A bitter thought, when she recalls her own situation.]
Right now, though, we don't know of any safe way of sending people home, and the warden insists that even if he wanted to, it's impossible to send people home once here.