At the start of this so-so standalone from British author McGeorge (Guess Who), journalist Robin Ferringham receives a call from Matthew McConnell, the sole survivor among six college students who vanished the year before during a boat ride in the Standedge Canal Tunnel, England's longest canal tunnel. Matthew, who's charged with killing his comrades and hiding their bodies, awaits trial in jail. Matthew wants to share details of a conversation he had with Robin's wife, Samantha, shortly before she disappeared three years earlier. After hearing Matthew's story, Robin, who has just published a wrenching memoir about Samantha, turns detective. In Marsden, the town at one end of the tunnel and the home of the five missing young adults, Robin finds a conspiracy of silence. After surviving a violent attack inside the tunnel, Robin is drawn into a stranger, more dangerous quest to figure out exactly what happened to the Standedge Five--and how Samantha's fate is entwined with their disappearance. Though McGeorge vividly evokes the setting, the convoluted plotting and easily guessed resolution undercut the mystery's effectiveness. Fans of historic English canals will best appreciate this one. Agent: Hannah Sheppard, DHH Literary Agency (U.K.). (Sept.)