The mysterious disappearance of a Scottish fishing trawler and a death on-board the submarine HMS Vigil bring the police into conflict with the Navy and British security services. DCI Amy Silva and DS Kirsten Longacre lead an investigation on land and at sea into a conspiracy that goes to the very heart of Britain’s national security.

• Suranne Jones
• Rose Leslie
• Romola Garai
• Gary Lewis
• Chris Jenks
• Jonathan Ajayi
• Amir El-Masry
• Oscar Salem