It's the early sixties, and the wife of Henry Sommers, the leader of the notorious Winter Hill Gang, is brutally murdered in her Boston hospital room, resulting in a gangland war lasting over thirty years and throwing a close-knit Irish family into a whirlpool of violence, deceit, and heartbreak. On Monster Hill, Henry's first reaction is to launch wholesale revenge against the man responsible for his wife's murder. But his somewhat level-headed lieutenant, Sammy Cunningham, convinces him getting even that way will only make things worse for him. Henry finally acquiesces. The problem is, he's already unleashed the northeast's most ruthless enforcer, Jay O'Malley, who'd do anything to please his boss, and, after discovering Sammy's begun an affair with his seventeen-year-old sister, Claire, to hurt Sammy.