Junior high footballers Ken and Mac (the great) get a chance to practice their detection and their tackle on a Saturday that begins with their soliciting at the shopping mall for the sick children's Jimmy Fund. First a jewel thief with the cops on his tail stuffs a locker key into Ken's collection can just before he's picked up; later an obvious accomplice drives by and buys Mac's can for twenty dollars (the boys having luckily switched spots in the meantime). Rash Mac's insistence on reporting to his policeman buddy at the bus station instead of checking in at the nearest precinct brings the boys face to face with one of the perpetrators--and, what with their second-string experience as left and right tackle, it's soon all' over but the reward. This is Corbett's master play at its trimmest--where another writer would have to fill you in on the origin of the term Jimmy Fund, Corbett sheds such padding. Easy to follow, and timed to a T.