Kids know there's a chasm between littering (""it makes the place look lived in"") and vandalism, but adults don't always make the distinction, which is why Lemon and his gang are in trouble with Crabbic--Mr. C. B. Crabtree--who accuses them of snapping off the tops of his lilac trees. To clear themselves, they conspire to catch the culprits while they're breaking up something else. Sneaking out at night is the first problem (Helen can't shake little sister Jeannie, David's feet dangling outside the window alert his parents); winnowing out suspects in the suddenly sinister park is another. When they do close in on a leather-jacketed crew smashing windows in the new school, Lemon and his Patrol are the ones who are almost intercepted, and Victor the Brain loses his identifying mouth organ. They incriminate themselves further trying to get it back, but at last Lemon's often questioned leadership and Shutter's newly-loaded camera pay off--they snap the vandals in the act, and rally the neighborhood with a reverberating ""Kellee-ellee-ellee!"" This lacks the originality and elan of Louie's Lot (517, J-193) but it has a cutting edge of honest mischief honestly recognized and crisp, wry characterization plus some unaccented asides on life in a British New Town.