The past returns to haunt Detective Superintendent Tennison in this, the best of the three 'Prime Suspect 4' episodes. The tortured and beaten bodies of two new murder victims display identical characteristics to the bodies of George Marlow's victims; the intriguing problem is that Marlow is in prison, suggesting that either a copycat killer is at work, or Tennison, the detective on the original case, put the wrong man away. This engrossing drama captures something of the tense, urgent tone of the earlier 'Prime Suspect' stories, with Tennison endeavouring, despite both personal and professional pressure, to get to the truth.