Supernatural (2005)

S10E15 The Things They Carried

Against Dean's wishes to abandon the search for a cure for the Mark of Cain, Sam persists in his research. Sensing that Sam is concealing something, Dean shifts his attention to a new murder investigation, where they encounter Cole. The trio joins forces and discovers that a Khan worm is responsible for infecting men and inciting them to kill. Sadly, the worm eventually infects Cole, complicating their mission further.