For the series finale, the five remaining celebrities endure intense interrogation. The interrogators subject the exhausted and hungry recruits to punishing techniques as they attempt to unpick their cover story and reveal their true mission.

Twelve celebs remain deep in the punishing environment of the Vietnamese jungle. Their trust in each other and themselves is tested in a task so gruelling that they start dropping like flies.

For the penultimate phase of the course it's survival of the fittest during a bout of pontoon wrestling. The remaining recruits are then ordered to head off into the jungle on a risky mission behind enemy lines.

The celebs face a punishing search operation through a series of rooms filled with CS gas. And they're tested under pressure during a rescue mission when they're tasked with extracting two of their fellow recruits who've been taken hostage.

The celebs first climb up a 200-foot cave, and abseil back down again. The second task is murderball: a serious test of physical strength and aggression. Finally, the recruits must write a 'death letter' to their loved ones.

The celebs engage in hand-to-hand combat against the directing staff, run down a 50-metre pillar and go diving for essential supplies. Meanwhile, one recruit is medically withdrawn.

16 celebrity recruits are pushed to their limit in the unforgiving Vietnamese jungle. The new recruits must first traverse parallel metal bars suspended 50 feet above the ground. Then they must fight against each other in the rawest form of combat.

The 12 celebrities take on hand-to-hand combat, then put their wits to the test in a hostage rescue mission. With tension mounting, two of the recruits are soon heading home.

The celebs do pair work as they descend 100 feet down a rock face, force march and carry a 40kg fuel drum over rough terrain. By the end of all this, some will be heading home.

Twelve celebrities head out for the wilds of the Scottish Hebrides for a series of full-on challenges in a gruelling version of the SAS selection, including an aerial assault course.

The remaining eight celebrities must pull themselves across a 300-foot-wide ravine, before dropping 160 feet to the extraction point. Then to weed out the weakest recruits, the celebs take a midnight beasting, and make an emotional call home.

The last five recruits are on the run from a specialist hunter force who are trying to track and capture them. If captured, the recruits will face the most psychologically demanding of all the phases, interrogation.

The last five celebs are put through two gruelling tasks, before being sent on the run for an escape and evasion manhunt. Who has the mental resolve to make it to the end?

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.

Twelve celebrities, from Katie Price to Joey Essex, leave their glamorous homes to take on the SAS selection course, the toughest challenge of their lives. Who will pass this test?

In the second selection phase, the celebs face murderball, a brutal beasting, a backwards helicopter dive into near-freezing waters, and a few home truths.

The recruits are put in pairs to eat, sleep and work as a duo, including a 60-metre cliff drop together. Can leaders Joey Essex and Lauren Steadman do teamwork or are they at risk?

The recruits face a killer 48 hours primed to expose the weakest members - including a beach beasting in near-freezing water and a gruelling race across mountainous terrain.

The remaining celebs face a punishing race across land and ocean before they plunge into an overnight pursuit by an elite hunter force across the Scottish Inner Hebrides.

As the climax of the current series, the last six celebs go through 48 hours of torture for the interrogation phase. Only the physically and mentally elite will make it to the end.

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.