 The unsolved crimes unit re-opens one of Jack s old cases when they investigate the murder of Chris Springer who out of fear for his life, offered to grass up Derek Hadley, a suspected drug dealer at the time. Jack retired before the end of the case but Springer s dismembered body was found soon after and Hadley, whose nickname was Chopper, was a suspect. Suspicion falls on the then investigating officer who may have been bent. Jack is also now receiving threats: his tires are slashed and his home is ransacked. Brian and DI Tina Murray go undercover to get the goods on Hadley.