Travis Aaron Wade

Crowley notices Dean is becoming more and more aggressive. Dean tells him that’s the side effect of being a demon, but Crowley knows it’s something more - the Mark of Cain needs to be fed. Meanwhile, Sam is captured by Cole (guest star Travis Aaron Wade), an angry man who blames Dean for his father’s death years ago and wants revenge. Cole tortures Sam, hoping he’ll tell him where Dean is hiding. Hannah (guest star Erica Carroll) sees how weak Castiel is becoming as his grace continues to fade, so she makes a bold choice and asks Metatron for help.

Despite Dean's directive to forget about looking for a cure for the Mark of Cain, Sam continues to do research. Dean suspects Sam is hiding something but decides to focus on a new murder case where they run into Cole. The three team up and learn a Khan worm is infecting men and turning them into murderers. Unfortunately, the worm makes its way into Cole.