June 1939. Francis Dempsey and his shell-shocked brother Michael are on an ocean liner from Ireland bound for their brother Martin's home in New York City, having stolen a small fortune from the IRA. During the week that follows, the lives of these three brothers collide spectacularly with big-band jazz musicians, a talented but fragile heiress, a Jewish street photographer facing a return to Nazi-occupied Prague, a vengeful mob boss, and the ghosts of their own family's revolutionary past. When Tom Cronin, an erstwhile assassin forced into one last job, tracks the brothers down, their lives begin to fracture. Francis must surrender to blackmail, or have his family suffer fatal consequences. Michael, wandering alone, turns to Lilly Bloch, a heartsick artist, to recover his lost memory. And Martin and his wife, Rosemary, try to salvage their marriage and, ultimately, the lives of the other Dempseys.