As longtime fans know, erratic veteran Moyes is capable of both topnotch puzzles (like, most recently, Who Is Simon Warwick?) and enervating tangles--like this new case for the increasingly tiresome Chief Supt. Henry Tibbett and his wife Emmy. The implausibilities begin when Henry and Emmy return from a quick holiday in Amsterdam via ferry--only to find themselves caught up in a murder/theft mystery: during the night someone in the sleeping ""saloon"" (for those without cabins) sticks a stiletto into the neck of ""Albert Smith,"" a minor, alias-ed crook who seems to have been carrying a fortune in just-stolen diamonds. Everyone on board (except the Tibbetts, of course) is searched--but no sign of the gems is found. . .until Emmy finds them in her bag after arriving home! So the ensuing investigation is complicated by a series of assaults on poor Emmy by would-be thieves--one of whom promptly commits suicide after failing to get away with the diamonds. Is it just a coincidence that the night-ferry passenger list included the granddaughter of the Dutch diamond-tycoon who was the heist victim? Was ""Smith"" murdered by his own employer (a shadowy mastermind) or a rival thief?. Why do several of the night-ferry passengers seem to be keeping dark secrets? Those are a few of the questions that are repeatedly pondered here--in stodgy, hoary dialogue. (Henry keeps saying things like, ""Damn it, Derek, we're up against a completely ruthless thief and murderer."" But the answers don't emerge until after an unconvincing trap/ showdown aboard the ferry--with all the suspects on hand to reveal a half-intriguing, half-ludicrous web of deception, blackmail, and psycho-villainy. Passable diversion overall--but many Moyes readers will be disappointed by the lumpy style, slapdash characterization, and contorted plotting.