The widow of a fugitive from the future calls Lambert with a request. She doesn't believe that her husband is dead, and asks that he investigate what has happened.

Her husband worked as a jailer, but when he opposed the warden, he was interned himself. When Lambert shows up, asking questions, he is also imprisoned.

The warden runs a very tight jail. The prisoners must dig for diamonds in a mine, and punishments for disobedience are severe. And Lambert of course has to release SELMA to his captors. Now it's a question of how he will get out of there before the warden decides to kill him.