It's a baptism by fire when new recruits Jamie Dow and Alex Leonard join the SAS's elite fighting force team. Hot on the heels of an explosive hostage-rescue exercise in the regiment's Killing House, Red Troop led by charismatic Sergeant Henno Garvie is called to take command of a bank siege. This time the life or death situation is dramatically and tragically real.

The firefight against French Special Forces aboard the Dowager Joan has left Jem dead and Caroline in a coma, while the rest of Red Troop face a full judicial inquiry that could land them in jail. Dempsey tries to rally the troops but Louis and Jamie don't want to toe the party line. And the men are shaken up by the arrival of a tough new troop commander, Captain Ian Macalwain.

Red Troop is called to a siege at a religious commune where Gulf War veteran Omega is holed up with his disciples after shooting dead two police officers. Henno is reluctant to attack with children in the house, but then Omega turns his guns on a follower. Going through an underground culvert, the SAS must act silently and decisively. But things are getting messy in their personal lives...