An obvious villain and an archetypal misunderstood youth are on the scene for a mild-mannered mystery about four girls and the abandoned house that becomes their neighborhood hideout. Mary Jane, who believes herself to be an ordinary 12-year-old, tells how the girls gain entry and how, with nearby buildings going up in flames attributed to arson, she and friends Heather, Donnavita, and Rainbow begin sleuthing in order to protect their territory. They have foiled two arson attempts before Mary Jane encounters the insurance-hungry owner and prevents his third fire from spreading. Why the author trots out such a clichÇd plot remains a mystery, but Griffin—who has written such original tales as Hobkin and Otto From Otherwhere—does give the story a lift with some realities of urban living: dope-smoking teenagers, crowded housing projects, tenant/landlord issues, gang graffiti; and the girls' varied personalities are well drawn, their bickering comfortably familiar. But they react to the clues in dribs and drabs; most readers will outpace them on the guesswork. (Fiction. 9-12)