We rejoin the Bluestone 42 team after the IED explosion has hit their mastiff.

The team are called out to a major operation, where events take a worrying turn.

Towerblock is put through his paces after challenging Rocket to a battle of the fittest.

The team suffer a Taliban attack, which distracts Ellen and Bird from their bickering.

Ellen has to learn to bend the rules, while Mac and Rocket do gladiatorial combat.

As the team prepare to leave Afghanistan for good, Simon receives some devastating news.