Heading out to the Med and the Black Sea, the 280 men and women onboard face a heart attack, a man overboard, and a show of force from Russian airplanes.
The ship is heading towards Crimea, when a Russian ship HMS Duncan is tracking disappears. The crew discover that the missing ship is a spy vessel and the Russians are also tracking them. As they approach Crimea, the situation escalates.
Reports that a chemical weapon has been used in Salisbury changes the mood on-board. The crew is on guard as it heads towards Montenegro when a chemical attack in Syria sees the Duncan go to action stations.
7 months at sea with HMS Duncan comes to an end with a tense stand-off against Russian warships which are threatening to fire on them if they launch missiles into Syria. Meanwhile, Danny goes for promotion and Liam is disciplined.
