The fatigued recruits drop from a helicopter into 4°C water carrying 20kg backpacks, before making their way to shore as a group then racing to the top of a mountain. Dripping wet and being lashed with 60km/h winds leaves one recruit in a hypothermic state.

Recruits are brutally awoken by the sound of gunfire and a botched rescue attempt unfolds. Messages from home test the recruits' emotional resolve while a relentless pack march takes its toll.