When a prominent French politician is found dead on the border between the UK and France, presumably under the sea, detectives Karl Roebuck and Elise Wassermann are sent to investigate. The police are forced into an uneasy international alliance after a shocking crime scene discovery.

The quiet family life of Nels Coxman, a snowplow driver, is upended after his son's murder. Nels begins a vengeful hunt for Viking, the drug lord he holds responsible for the killing, eliminating Viking's associates one by one. As Nels draws closer to Viking, his actions bring even more unexpected and violent consequences, as he proves that revenge is all in the execution.