SAS Australia 2-5

Selection. The final four recruits face their greatest test: a petrifying helicopter insertion into enemy territory, where they must cover their tracks before retrieving a bag from a 100-metre-high cliff face.

Guts. Seventeen celebrity recruits have the guts to sign up for the most brutal Special Forces selection course. Their first initiation is to be set on fire, and then survive a plane crash simulation.

Control. The celebrity recruits are submerged in a vehicle underwater, forcing them to control their panic while holding their breath. They also undertake a covert drill, to test their integrity.