G.K. Chesterton's Father Brown is one of the most beloved characters in the mystery/thriller literary canon. If The Detective, which brings him to film in the person of Alec Guinness is not quite a top-notch mystery film, it's certainly not for lack of trying on the actor's part. Guinness is an ideal Father Brown, and from the moment he is first discovered onscreen -- putting money back in a safe as a flashlight blinds him -- Chesterton aficionados (as well as just plain movie fans) know that they are in good hands. The actor puts on a mask of timid bemusement, his face seeming to suggest that his eyes are still trying to become accustomed to his nose and none of them really seem to know what to make of this strange mouth that insists on hanging around them. But all features spring to attention when he is on the trail, aiding one of the gentlest sleuths in the cinema's history. Guinness is aided by a strong performance from a young Peter Finch and the traditionally solid work of the unique Joan Greenwood, underutilized here, but welcome nonetheless. If the screenplay could be livelier in places, it still hits its marks, and Robert Hamer's direction is serviceable, if not as imaginative as one might wish. These failings keep Detective from being the first-rate film it could have been, but with Guinness around, it's hard to care.