The crew of HMS Duncan face their most important mission to date when they receive orders to join a French aircraft carrier carrying out airstrikes against ISIS forces in Iraq and Syria. For the crew, this means seven solid months at sea.

The crew must defend French aircraft carriers off the coast of Syria, and help evacuate Britains being held in Cyprus.

The crew have been sent to Ukraine, but the unexpected absence of Russian ships leaves everyone unsettled.

When Iranian forces take control of the British flagged tanker Stena Impero, Duncan is ordered to the region.

As Iran still holds the Stena Impero, Duncan is ordered to continue escorting fuel tankers safely through the Strait of Hormuz.