Casca is soon flown out to French Indo-China as well where the Vietnamese communists, the Viet Minh, are fighting to throw the French out, and Casca meets up with his old comrade. One of their first missions is to ambush a top-ranking Viet intelligence officer called Thich. The ambush goes well but Thich escapes, unlike most of his men, but in the aftermath Thich vows to take revenge on Casca. Thich believes his sister betrayed him and goes to Hanoi to find out, accompanied by a squad of men. They break into the French intelligence HQ where, by co-incidence, Casca and Gus are on guard duty. Thich kills his sister and takes Casca prisoner, taking him back to the jungle and into a subterranean hideout. There, Thich interrogates his prisoner but learns nothing.
Meanwhile Gus falls foul of the brutal sergeant-chef Hermann and gains revenge in a number of underhand ways. While this happens Casca escapes from his prison and kills a number of Viets before being gunned down and left for dead. thich himself examines Casca's body and is satisfied his former prisoner is no more. However, he rises from death once more to return to his unit. By this time Gus has befriended an Italian called Dominic and the two have continued the personal war with Hermann. Casca is sent to report to General Navarre, the man in command of the French forces in Indochina, for an intelligence report of his imprisonment. Shortly afterwards Navarre decided to risk all in an attempt to break the enemy at a place called Dien Bien Phu.
Casca, Gus, Dominic and their units are then flown out to the French outpost at Dien Bien Phu where the Viet Minh are massing. They are soon cut off and bombarded by masses of Viet guns and slowly the trap is closed. The three men befriend a Viet volunteer called Xuan and the four go out on patrols at night to gather intelligence. However, enemy attacks continue relentlessly. Gus kills Hermann before the final attack takes place, and the night before this the French commander decides to ask his men to either surrender or fight their way out. Casca and his comrades decide to escape and manage to fight their way out before Dien Bien Phu gives in. In the struggle Casca comes face to face with Thich who dies of a heart attack in fright.
The defeat spells the end of French Indo-China and Casca, Dominic and Gus are flown out back to Algeria where the Foreign Legion has more dirty jobs for them.