A street shooting which leaves a mother and child dead on the school run. But was this a random act of violence? Unlikely, when it transpires the victims were the wife and son of well known drugs baron Mansel Shale.

Having committed this atrocity, the gunman flees to a charity shop where very soon a hostage situation develops and Harpur and Iles are brought in to oversee the siege - which ends in sudden action and tragedy.

But as subsequent events unfold, it appears the gunman was on target; he wasn't after Shale after all, but his wife - who was certainly not what all had assumed her to be...