Piknik (1968)

Pacific Island - 1945. Five American soldiers were sent to reconnoiter the Japanese rear. Surrounded by unpredictable jungle and terrible heat, they have been moving in unknown territory for over two weeks in order to find the enemy. Commander Grackmiller, due to the fatigue of the rest of the platoon, takes it upon himself to scout the area ahead of them, and the soldiers Smile, Burda, Tall and Rozden are to wait for him and hold position. The heat to kill, exhaustion and nervousness soon begin to take a toll on their sanity and morale. Unafraid to say anything to each other's faces, vigilance and caution are completely gone and paranoia and suspicion take over instead. After a while, strange noises start coming from the jungle, which Smile goes to investigate, and comes back pale as death...