Man's Best Friend With Benefits

S8 E15: Dean really doesn’t like witches! A police officer (guest star Christian Campbell), who turned to witchcraft after working a case with Sam and Dean, is plagued by nightmares in which he murders innocent people. However, when the murders actually happen, Sam and Dean are called in by the witch’s “familiar” (guest star Mishael Morgan) to help – but the brothers aren’t sure they want to save a witch.