Pastor Montgomery Childs has tended his flock in Johnstown, Pennsylvania, for two years. While his pews are full every Sunday, he most desires to see a reckoning between God and the kings of industry who recreate on Lake Conemaugh. The pleasure grounds, flowing alcohol, and business dealings of the South Fork Fishing and Hunting Club taunts Monty as he works to heal the wounds inflicted from his own privileged childhood among Pittsburgh society. Like Noah, Monty prays against the evil surrounding him, but he never expects God to send a flood.

It takes five days for the Red Cross to respond to the Johnstown flood disaster, but when it does, Annamae Worthington is ready to help. Apprenticing under Clara Barton has prepared her for the job, but nothing can prepare her for the death and destruction that awaits. As if the survivors haven't suffered enough, typhoid fever ravages the town, resurfacing suppressed emotions regarding her father's death.

Narrowly surviving the flood and the horrifying things he's witnessed, Monty's faith is floundering. Then a Red Cross nurse puts him to work helping with the typhoid fever victims arriving at the hospital tents every hour. Monty and Annamae work together distributing disinfectants and supplies, housing orphans, and serving those left behind. Slowly, his faith resurfaces. A kinship forms between them neither can ignore. But when an investigation into the collapsed dam points to the South Fork Fishing and Hunting Club, secrets emerge that may tear them apart.