When the bell rings, the Den gives the guest one hour's grace, as a courtesy. At the end of the hour, every door is closed, every purreus is refused and every friend list in the building goes quiet at once. The guest may stay in the lobby, but nobody will bring them water, and that is the part that hurts.
There is a way back. It is long, it is sincere, and it involves helping someone fix their avatar's eyes for an hour without once saying “well, actually.”