Lawyer-detective Arthur Crook always believes his clients are innocent... despite the evidence to the contrary.
Classic crime from one of the greats of the Detection Club

A famous art collector's car discovered at the bottom of a cliff after he was supposed to have taken a young woman to the railway station, so naturally the police expect to find his body there, too. But it turns up weeks later, in a locked room in his country house, and he's been stabbed to death...