Detective Superintendent Sandra Pullman heads The Unsolved Crime and Open Case Squad (UCOS), cracking previously unsolved crimes from the past. Her team are three ex policemen; Gerry Standing, Jack Halford and Brian Lane, who have all opted for early retirement. The Series 8 cases include investigations into the murder of a Natural History Museum palaeontologist with plenty of enemies, a previously unidentified vagrant, a charred body with potential links to an Albanian crime circle, a popular market stall holder, a bicycle courier in possession of a deadly package, an antiques dealer and a prominent scientist who disappeared while on a train to Paris. But as UCOS dig deeper they begin to rattle cages at Whitehall and an ominous warning is issued.