For three decades one of the most secretive units in the British military has been a mystery force known as X Platoon.

Officially there was no X Platoon. The forty men in its elite number were specially selected from across the Armed Forces, at which point they simply ceased to exist. X Platoon had no budget, no weaponry, no vehicles and no kit - apart from what its men could beg, borrow or steal from other military units.

For the first time a highly decorated veteran of this specialised force - otherwise known as the Pathfinders - reveals its unique story. Steve Heaney became one of the youngest ever to pass Selection, the gruelling trial of elite forces, and was at the cutting edge of X Platoon operations - serving on anti-narcotics operations in the Central American jungles, on missions hunting war criminals in the Balkans, and being sent to spy on and wage war against the Russians.

The first non-officer in the unit's history to be award the Military Cross, Steve Heaney reveals the extraordinary work undertaken by this secret band of brothers.

Steve Heaney joined the Parachute Regiment Juniors at sixteen, then passed Parachute Regiment selection and joined 3 PARA in 1987. Three years later he successfully undertook selection into X Platoon - more formally known as the Pathfinders. He went on to serve with that unit for over a decade, working with almost every Special Forces unit with which the British military has links. In 1999 he was promoted to Platoon Sergeant. The following year, he was the first non-officer in the unit's history to be awarded the Military Cross for his leadership and courage during Operation Mayhem.

Sergeant Heaney left the British military in 2001. Since then he has worked in the Middle East as a senior military advisor to one of Britain's key allies.

Damien Lewis worked as a war- and conflict-reporter for major broadcasters across Africa, South America, the Middle and Far East, and has won numerous awards for his journalism. In 2001 he wrote his first book, an international number-one bestseller translated into over thirty languages and made into a film and stage play. His Special Forces books OPERATION CERTAIN DEATH, ZERO SIX BRAVO and CHURCHILL'S SECRET WARRIORS were SUNDAY TIMES bestsellers, as were his co-authored military books, FIRE STRIKE 7/9 and IT'S ALL ABOUT TREO. Several of his elite forces books are in the process of being made into movies or TV dramas.