Librarians, a train, a murder, and the end of an apprenticeship. Young Lemony Snicket's chaperone, S. Theodora Markson, has crept out in the middle of the night. Following her, he receives an origami message from one of his associates (a word that here refers to the people around his age with whom he shares the goal of stopping the villainous Hangfire from destroying the ink-manufacturing town of Stain'd-by-the-Sea). The message leads Snicket to the railway station, where a train is about to depart Stain'd-by-the-Sea for the city. The train's taking both Snicket's former associate Ellington Feint and librarian Dashiell Qwerty (the latter unjustly accused of arson) to the city to await trial. With no ticket, it takes a feat of derring-do to get aboard. When he does, Snicket nearly witnesses a murder...which he then must solve while attempting to keep Hangfire from obtaining the statue of the Bombinating Beast, the final piece in his dastardly plan. With a train half full of suspects, Snicket's lucky the other half are his associates. Can they trap Hangfire and catch a murderer? Author Snicket (aka Daniel Handler) closes his quartet of smart, noirish mysteries detailing the early training of the chronicler of the woes of the Baudelaire children with several bangs (and a poison dart or two). Most questions (wrong and right) are answered by the satisfying close. Best to start at the beginning, but the whole's an enjoyable ride. (Mystery. 8-14) COPYRIGHT(1) Kirkus Reviews, ALL RIGHTS RESERVED.