School of Fear (1969) on Netflix

Plot summary

Inspector Klevenow and his police take charge when Kurrat, a student at a boys' boarding school in Northern Germany, disappears one night after a quarrel with a teacher and tells nobody where he is going. The officers question the people around the boy. They describe a rebellious student, admired by many classmates, despised by some out of jealousy, and disliked by a few teachers. Nobody can say whether Kurrat is dead, whether he is playing a macabre joke, or whether jealousy, disappointment or betrayal is behind his absence. A rumor at the school linked him with the teacher Stallmann. Some ask whether he was killed and his body put into the nearby sea.