In 1920s Chicago, elite agent “Death God” Will witnesses his mentor Mack murdered by the criminal syndicate The Black Cross. Dying, Mack entrusts Will to protect his daughter Lillian, her little son Andy and a vital secret. Will fakes his death and hides as diner worker Cain to secretly guard the mother and child. While fighting gang harassment, he uncovers a shocking collusion between corrupt officials and The Black Cross. Facing deadly crises, he teams up with an ally to fight the hidden evil.