Sam (Jared Padalecki) learns that former Men of Letters, Magnus, once built a magical box and Sam sets out to find it in the hopes it can cure Dean (Jensen Ackles) of the Mark of Cain.  However, what he’s not prepared for is the deadly alarm system Magnus set up on the box.  When Sam opens the box, he puts both his and Dean’s life in danger.  Stefan Pleszczynski directed this episode written by Robert Berens (#1019).