March 4th 2002. The largest land battle of the Afghan War is raging around a remote valley. U.S. forces, aided by friendly Afghans, are moving in using classic 'Hammer and Anvil' tactics to crush a force of up to 1000 foreign Al Qaeda die-hards. At Bagram Air Base, a Rangers Special Operations Quick Reaction Force takes off at 04:45 hours. Its mission - to rescue a missing Navy Seal. As their chopper, 'Razor One', approaches the LZ, no one on board has any idea that they are flying straight into a nest of concealed Al Qaeda bunkers - until four RPGs slam into them. As the chopper crashes and starts to burn, the door gunners give frantic covering fire while the Ranger scramble clear. This programme tells the dramatic story of the 21 men on board 'Razor One' and their desperate fight to survive which has become known as 'The Battle of Roberts' Ridge'. The story is supported by real gun camera footage and exclusive interviews with U.S. commanders, soldiers and F-15 and F-16 pilots involved in the operation.