In Depression-era Chicago, Michael O'Sullivan is a good father and a family man--and also the chief enforcer for John Looney, the town's Irish Godfather of crime. As Looney's "Angel of Death, " O'Sullivan has done the bidding of Chicago gangsters Al Capone and Frank Nitti as well--but when a gangland execution spells tragedy for the O'Sullivan family, a grieving father and his twelve-year-old son find themselves on a winding road of treachery, revenge and revelation.