As Ben knows, having been served some by a Spanish friend, the ""funny bananas"" that guards are finding in the Natural History Museum (along with green paper plates and other scraps) are platanos. Being friendly with the guards (both his parents work as scientists at the museum), Ben also hears about the senseless night vandalism that has them stumped, and in his efforts to solve the mystery he begins following a girl who carries food around in a fake book. . . . Turns out it's for her pet coatimundi named Frito whom Carmen has let loose in the museum, and in the end there's the obligatory mad chase as Ben and Carmen try to catch Frito before the exterminators get to him, Frito hides in the mouth of Tyrannosaurus Rex, and later all three collide with a space freak who is stealing pre-Columbian gold to use in his inter-galactic communication machine. This is far lighter and less ambitious (pretentious?) than McHargue's recent Stoneflight (KR, p. 70), but despite the frenzy he causes Frito never runs away with you. Some might object to Carmen's stereotypical depiction, except that no one else--parents, guards, policeman, Ben himself--is any more individualized.