Kathryn Morrissey used to be a Christian missionary, but she lost her faith after her family died in a tragic accident Now, she uses her skills to disprove religious things. When a small town is hit by a series of biblical plagues, Katherine goes there to show that a supernatural force isn't to blame. She soon finds that science can't explain what's going on. Instead, she must find her faith again to fight the evil that lurks in a Louisiana swamp.