Series 4

14 celebrity recruits face the toughest course to date, played out in the unforgiving terrain of the Jordanian desert. The recruits face an intense start to the course, crawling through sand in blistering 40-degree heat, before facing a gas attack.

The celebrity recruits must jump from a helicopter in pairs. Next, they take the life of a teammate in their hands as one of them free-falls from a 150-foot cliff, being kept from crashing to the ground by their partner.

The recruits take on the gruelling task of moving a broken-down one-tonne Jeep in searing heat and through thick sand. Then the celebs must balance on ropes 160 feet above the ground to cross a ravine.

The recruits must make split-second decisions about whether to shoot in a simulated warzone. Then the recruits are forced to dive backwards from a seven-metre platform into the Gulf of Aqaba in the dead of night.

The recruits compete in three brutal challenges that test their leadership skills. First they must construct a zipline, then go head-to-head in murderball, and finally they must work out how to pull a 200kg sled loaded with equipment up a revine.

The celebrities face the penultimate survival phase of the course, where they prepare for life on the run behind enemy lines. An ambush triggers traumatic memories for AJ Pritchard. Messages from home threaten to unsettle the recruits ahead of the escape and evasion phase, while Calum Best leads his team astray as they try to avoid capture by a relentless Hunter Force

The last seven celebs face the final brutal phase with a punishing interrogation with ice baths and burial to force a confession. Will they crack or make it through to the end?