The Bluestone 42 team are called out on routine ops with their CIA liaison officer Carter, where things take a drastic turn. Back at base, they are introduced to Mary, the new padre, who Nick, the Ammunition Technical Officer, takes an instant shine to. Meanwhile, Simon grapples with Millsy over the report that Nick has forced him to write on his behalf, and the young Privates - Mac and Rocket - enjoy winding up Bird who may or may not have named the bomb seeking robot 'Arthur'.