Rain Falls Like Mercy opens with the investigation of a young girl's murder in Wyoming in mid-1941. Tom Call, the young sheriff in charge of the case, falls in love with Juanita, the wife of Eli Paint, whose son Leo and grandson Bobby Watson are on duty with the U.S. Navy. Almost overnight, the case is derailed by the Japanese attack on Pearl Harbor, disrupting the lives of all involved. Tom joins the U.S. Air Force and is deployed to England to fly bombers, while still trying to pursue his murder investigation. His suspicion falls on Pardo Bury, the psychotic son of a wealthy rancher in Wyoming.
As Pardo and Tom make their ways to their inevitable and shattering confrontation, Rain Falls Like Mercy displays Todd's uncanny ability to zero in on his characters' emotional lives while simultaneously painting an epic picture of the historical events that shape their destinies.