Has anyone else been watching Vigil on BBC1? This whodunit murder mystery started with a double bill last Sunday and Monday, and episode 3 is tomorrow night. It centres around HMS Vigil, which is a Vanguard class Trident nuclear submarine. A crewmate is found dead onboard, but as it can't return to base because it is an active deterrent, a police Investigator is sent onboard at sea instead. Gripping!