The first series follows the training of 25 prospective members of the Mountain and Arctic Warfare Cadre (MAWC) as they experience the extreme environments that they will face in combat.
Training for 25 potential Royal Marines Mountain and Arctic Warfare Cadre begins.
Living off the land isn't as easy as it looks, so a bit of scavenging helps.
Five days into a survival course on the Hebrides, and still no food.
Death is just part of the job, so don't hesitate if the enemy comes into sight.
'Direct action' - break into a fort and plant high explosives on a radio mast.
The final stage of training - a 200 mile yomp through the snow - easy!
The trainees complete their recruitment course and discover if they have passed.