Fifty recruits arrive at camp as they begin training for the Royal Marines.

After four weeks, some recruits are still trying to adapt to the rigors of the program, while the mud run looms on the horizon.

The recruits are taught survival skills, including hunting and killing for their dinner.

Second Lieutenant Bertie Kerr is followed as he trains for deployment to Afghanistan.

Halfway through their commando training, the recruits of 924 Troop are pushed to new physical and emotional limits prior to their deployment to Afghanistan. Meanwhile, Second Lieutenant Bertie Kerr, just three weeks out of training, leads his troop into enemy territory and comes under fire from the Taliban.

Adam Collins of 924 Troop makes a shocking accusation against his training team after being admonished for failing to achieve high standards. In Afghanistan, Bertie Kerr and his comrades dig in on a remote mountain and brace themselves for a possible attack by Taliban forces.

Bertie Kerr and his men find themselves fighting for their lives as they embark on a dawn assault against an enemy-held mountain in Afghanistan. Back in Devon, the remaining recruits of 924 Troop are on their final military training exercise before they too will be deployed on the front line.

The successful soldiers fly to Afghanistan, where they join Bertie Kerr's 11 Troop to begin sentry duties as well as taking on day and night patrols in the war-torn country. The programme shows how the new recruits react to the harsh realities of battle and how those who have been taking part in the conflict cope with the death of a comrade.