In 1972, the story begins and ends in 2002. After a covert operation in 1972 during the closing stages of the Vietnam War, a team of British SAS troopers was flown from their training base in Borneo through to Thailand to assist a CIA operation in Vietnam. The rendezvous was to at all times be of a covert nature and never exposed to media.
During this operation, the SAS uncover atrocities by the CIA team on local village communities. This leads to a fiery confrontation between the two groups resulting in casualties. The SAS team complete their mission objective of bringing out a prominent North Vietnamese official but because of the altercation between the teams, they were forced into an alternative evacuation plan.
The CIA having been faced with the fact of the atrocities being known and the loss of their colleagues by the SAS go on a mission of vengeance which lasts over thirty years.