From the recruits' very first challenge - a terrifying backwards dive out of a helicopter - Ant Middleton and his team are determined to show there will be no allowances made. Later, the celebrities have to overcome more fears.

Chief instructor Ant Middleton and his directing staff put the celebrity recruits through a series of tests. One celebrity recruit collapses on a mountain and another is badly affected by the extreme cold, as they face brutal challenges.

The celebrities are paired up to prove that they're team players, and must put their lives in each other's hands, in a terrifying free fall abseil. They must leave their celebrity world behind and learn to trust their partner to keep their place.

As the pressure is piled on, one recruit cracks and a bad decision puts another's place on the course in dire jeopardy. After being pursued through the Chilean countryside by a military hunter force, the recruits enter the interrogation phase.

The remaining celebrity recruits face a final, brutal challenge at the El Morado glacier, 3000 metres above sea level. A dozen celebrities started, but only a few have what it takes to complete the course.