A brilliant but idiosyncratic British detective and his resourceful local team solve baffling murder mysteries on the fictional Caribbean island of Saint Marie.

When a fearsome and ancient species emerges from the ocean, dramatically revealing themselves to humanity, an international crisis is triggered. With the entire population at risk, UNIT step into action as the land and sea wage war.

A raucous black comedy about a gang of Grimsby Trawler-men who carry out the heist of a lifetime.