Sam and Dean allow themselves to be arrested in order to investigate a series of murders inside a penitentiary. However things get complicated when FBI agent Henricksen shows up to take over their case.

While Sam hangs on the edge of life and death, Dean appeals to the fallen angels for help. Unfortunately, most of them only see Dean as a means to get to Castiel and exact bloody vengeance on the one who caused them to Fall. Meanwhile, Sam wrestles with his inner demons and Castiel learns what it means to be human.