GH950102-000000 GH950102-000000 Alien treatment is still the biggest mystery n HARPUR & ILES ( BBC 1 ) - It ' s the oldest trick in the rule book , up there with the accused making a ``full and frank confession ' ' or ``falling down the stairs ' ' , but BBC 1 ' s new drama spins the good cop / bad cop routine like handcuffs on a tabletop , till both are just a blur . Hywel Bennett is the grasping and unscrupulous Assistant Chief Constable Desmond Iles , while Aneirin Hughes is the more-compassionate CID chief , Colin Harpur , forced to work the same case of kidnapping . Based on the novel Protection by Bill James , Harpur and Iles run_through the Cardiff underworld trying to recover the young son of an underworld boss , swiped as rival gangs battle over a protection racket . It ' s a chance to find