Twenty recruits prepare to enter `Jungle Hell', the toughest phase of SAS selection. First they are tasked with traversing the 'trainasium', suspended 50 feet above the ground. Then they must complete a 200-foot abseil headlong into a waterfall.

The recruits take part in extreme hand-to-hand combat. A breach of camp discipline leads to a 'beasting'. And a recruit gets stranded up a huge waterfall.

In the Vietnamese jungle, the group are tasked with a 200-foot abseil into a dark bat-infested cave. In a bustling market, the recruits must take down an armed gunman in a crowd of civilians. And then they take on each other in a game of murderball.

The remaining 11 recruits face a hostage rescue mission hoping to spring two abducted recruits. The second challenge is a punishing head-to-head team ammunition supply race in the jungle.

The seven remaining recruits are ambushed by a hunter force team behind enemy lines. Handed over to interrogators for questioning, the recruits must endure psychological and physical punishments designed to break their will and force a confession.