Trident nuclear submarine HMS Vigil becomes the site for a murder investigation when a dead body turns up on the vessel. Detective Amy Silva of the Scottish police undertakes the investigation but will have to do so while the Vigil remains active. Back on land, Detective Kirsten Longacre tries to peel back the layers of what may have led to such a killing. Both their work leads to unearthing a series of corruptive ties between the government and the British Navy. This crime thriller comes from creator Tom Edge and stars Suranne Jones, Rose Leslie, Shaun Evans, Martin Compston, Paterson Joseph, Adam James, Gary Lewis, Lauren Lyle, Lolita Chakrabarti, Anjli Mohindra, Connor Swindells, Cal MacAninch, Lorne MacFadyen, Daniel Portman, Stephen Dillane, and Stephen McCole.