A series of suspicious drownings all deemed accidents. A retired detective with an outlandish theory to prove. Families in eight states left without justice. PI Riley Sullivan is brought back into the worst case of her career. She and her team have two goals - prove the cases are connected and find the person responsible before they strike again.
It's not such an easy feat. Drownings are among the hardest homicide cases to prove and local law enforcement agencies don't want to get involved. A few rogue detectives know that something is amiss and are more than willing to share information with Riley and her team, who are forced to work separate cases states apart.
When all of the evidence starts to identify the most unlikely of suspects, they must race to New Orleans to uncover the truth and protect one of their own. Can they stop a killer before the next drowning?