Boom! is a children's science fiction novel by Mark Haddon published in 2009. It is the revised version of Mark Haddon's Gridzbi Spudvetch!, which was published in 1992. Boom! tells the story of two best friends, Charlie and Jimbo (a nickname for James). When Jimbo's sister, Becky, says that the teachers are going to send him to a school for mentally ill children, Jimbo and Charlie sneaked into the staff room, where they hid a walkie-talkie to eavesdrop on the teachers' conversation, in order to confirm what Becky said was true. None of the information they hear means anything (which points to the fact that Becky was just trying to scare Jimbo), except for the surprising fact that their teachers both Mr. Kidd and Mrs. Pearce is speaking another language. After a while of dangerous investig