Two teenaged children and their adult minder go missing during a storm while their parents are away for an extended weekend in Paris. Their mother believes they've drowned in the floodwater and when a t-shirt that unmistakably belongs to her daughter is found by the police, she is convinced of foul play. The detective on the case has his awareness heightened by the fact that his adult daughter is trying to extricate herself from an abusive relationship.
When the police learn that the son belonged to a fundamentalist Christian sect, everyone seems suspicious. Even the children's famous photographer grandmother.