Glasgow's Millside has a no-witness traffic accident and the deceased civilian becomes C.P.I. Thane's pigeon. When he comes up against a hot-car play, its tie-in to a popular racing driver, and the peripheral activities that link them together, Thane plugs away, delivers the action that his superior demands and winds up his case in the mountains of Inverness County. Tricka of the trade for this slow grind.