Kirsten’s investigation takes her into the heart of Scottish politics, but when she unearths a navy cover-up, it leaves Amy questioning who she can trust on Vigil.

With Vigil in danger, Amy must fight to continue her investigation. Meanwhile, Kirsten’s enquiries lead to tragedy.

When a crew member is found dead aboard the Trident nuclear submarine HMS Vigil, Detective Amy Silva is flown out to investigate.

Season 4 of Doctor Who premiered on April 5, 2008 | 13 Episodes During an alien emergency in London, a woman called Donna Noble must search for an old friend…