The Third Rail — Michael Harvey

A woman is shot as she waits for her train to work. An hour later, a second woman is gunned down as she rides an elevated train through the Loop. Two hours after that, a church becomes the target of a chemical weapons attack. The city of Chicago is under siege, and Michael Kelly, cynical cop turned private investigator, just happens to be on the scene when all hell breaks loose.

Kelly is initially drawn into the case by the killers themselves, then tasked by Chicago's mayor and the FBI to hunt down the bad guys and, all things being equal, put a bullet in them. Kelly, of course, has other ideas. As he gets closer to the truth, his instincts lead him to a retired cop, a shady train company, and an unnerving link to his own past. Meanwhile, Kelly's girlfriend, Rachel Swenson, becomes a pawn in a much larger game, while a weapon that could kill millions ticks away quietly in the very belly of the city.