This episode meets the infantry soldiers, or 'bullet catchers' as they call themselves. These troops are never more than 500 metres from the enemy, living in a world where injury and death are an occupational hazard.

In just a few months, three of the 15 soldiers based on a small compound on the frontline of Helmand Province are seriously injured: one by an IED (improvised explosive device); one by gunshot wound to the neck; and one by a grenade. It's a stark reminder of the risks they face each time they set outside the wire on foot patrol.

In spite of the dangers, the soldiers open up about their passion for fighting and the adrenaline-fuelled excitement of cheating death. One soldier describes it as 'better than sex' while another says, 'I'd take a good scrap over getting laid any day'.

But during moments of intimacy, rarely captured among soldiers, the young troops, some of whom are only 18 years old, lay bare their anxieties. James says 'I've never been so scared in my whole entire life', while Liddell tells of his horror at having to hang his kilt up before leaving home in case it was needed for his funeral.

As the tour progresses the soldiers are told they must push north, further into Taliban-held territory, to an area where one of their comrades was previously blown up by an IED. With no alternative but to follow orders, the soldiers' deepest fears become reality yet again.