The Dead Land (1) (S06E07)

A new serial killer is targeting homeless men, brutally stabbing them through the heart. In a strange twist, the bodies are washed and wrapped in paper before being discarded in the town's commercial district. Alex is pulled away from the investigation, and her role is filled by the young Oxbridge graduate, Hall. Though Tony is initially wary of him, he soon discovers that Hall has a psychology degree and admires Tony's work. Meanwhile, a more ominous admirer, clearly Bryant, is leaving unsettling 'gifts' on Tony's doorstep.