When a series of fatal accidents puts America's freight and passenger trains under siege, a Philadelphia-based band of railway buffs decides to investigate while the FBI (in hopes of sidetracking her) assigns a lone, inexperienced agent to the case: a technically competent but woefully predictable thriller from first-novelist Berson. Larry McBryde, a charter member of the Philly Foamers (so- called by impatient Amtrak officials because they almost literally foam at the mouth in their enthusiasm for railroadiana) heads the local transit authority's customer-service department. Concerned that someone might be sabotaging rail lines, he's badgered by fellow members into conducting an inquiry into some suspicious wrecks by fellow club members. Meantime, Jennifer Szczymanski, a rookie FBI agent who's been transferred back to Washington after bringing sexual-harassment charges against her boss in South Dakota, is detailed to look into the smashups. Aboard the Lake Shore Limited to Chicago on what could be its last run, she meets Larry, the unhappily divorced father of a precocious little girl named Melissa. The two hit it off, and Larry, who's figured out that the Lake Shore is the villains' next target, employs his special knowledge to avert a disaster. But circumstantial evidence puts Larry, who's being framed, at the top of her suspects list. They meet again on the Southwest Chief (which quick-witted Larry saves from incineration) and, after exchanging confidences, join forces just before Jennifer's obtuse superiors take him into custody. On the lam together, they reach Denver and hop the California Zephyr, which has a rendezvous with death in a long tunnel through the Rocky Mountains. With help from Jennifer, Larry pulls off another 11th-hour rescue. They then head east for a climactic shootout with the unsurprising bad guys who've kidnapped Melissa to lure them to Philadelphia's Reading Terminal Market. A fast ride of a debut along unfamiliar, often exotic, routes to a disappointingly foreseeable destination.