In Laos, 1954, eight days before the french defeat in the Indochina war, the 317th platoon – four french soldiers and 41 laotian combatants – has been ordered to leave its outpost and to retreat for the plains of Diên Biên Phu, where the french army is getting stucked. Led by the inexperienced and idealistic sous-lieutenant Torrens, fresh out of the military academy, and by adjutant Willsdorf, a WWII veteran of the Werhmacht, the group must cross 150 kilometers of jungle. But dripping rainwater, hostile nature, and the Viêt-minh ambushes expose them to constant danger.
