When they are in pain, most children regress to an infantile state and instinctively, blindly, call out to their mother. Sometimes to their father. Dean doesn't. He calls for Sam.

Dean and Cas are two world renowned serial killers, and begin a game of cat and mouse, leaving each other messages in their victims, winking/waving at each other on security cameras. Eventually, it's going to come to a head when they both pick the same victim; Sam Winchester. Inspired by a post from therangerofthenorth on tumblr.