Merrick Watts

Celebrities undertake a series of extreme tasks, including jumping backward out of a helicopter and hand-to-hand combat, as they begin the challenge of completing the grueling SAS selection course.

Recruits race up a snow-covered mountain dragging a 60-kg sled; exhausted, they must then swim under ice, battling hypothermic conditions, only to discover the weakest will be sent home.

Armed with rifles, the recruits are tasked with a hostage rescue mission before taking on their most dangerous assignment yet in near-freezing water.

In a dangerous backward fall, the life of the jumper is in the hands of a fellow recruit; during an honesty test, some astonishing truths are shared; a simple mistake results in a serious injury.

The fatigued recruits drop from a helicopter into 4 degrees Celsius water carrying 20 kg backpacks before making their way to shore as a group, then racing to the top of a mountain.

In a punishing day, recruits crawl across a jagged ravine on a single rope above the ocean, are submerged in crashing, cold surf, and face a physical drilling that leaves them on the brink of collapse.