As six British soldiers sit imprisoned in a hut in the jungles of Sierra Leone, their captors – a heavily-armed militia group known as the West Side Boys – are mostly sleeping. But unknown to either group, an audacious SAS rescue mission is moments away.

Zero Hour arrives as five helicopters carrying more than 120 paratroopers appear over the horizon, unleashing an awesome military strike on the unsuspecting rebel camp.

Operation Barras – the rescue of six members of the Royal Irish Regiment in Sierra Leone – was perhaps the most daring and impressive SAS rescue mission of all time.

It was described by one defence chief as the "most complex mission carried out by British troops in years"; Brigadier Andrew Stewart, who co-ordinated the mission from Permanent Joint HQ in North-West London, said of it: "As a purely military operation, it knocks the lifting of the Iranian embassy siege into a cocked hat."

Referred to by those involved as "Operation Certain Death", it was a precision military strike, in which weeks of careful planning came together in a perfectly coordinated hour.

This documentary looks at the circumstances of the raid, and the background to British involvement in Sierra Leone. It reconstructs the events of the operation in minute detail, speaking to those involved in its planning and execution.

Film Duration: 00:46