Mr. Mercedes : a novel
(Book)

A lone driver plows through the crowd in a stolen Mercedes in a distressed Midwestern city, running over the innocent, backing up, and charging again. In another part of town, months later, a retired cop named Bill Hodges is still haunted by the unsolved crime. When he gets a crazed letter from someone who self-identifies as the "perk" and threatens an even more diabolical attack, Hodges wakes up from his depressed and vacant retirement, hell-bent on preventing another tragedy.