The Wicker Man (1973)

A devout police sergeant arrives at a remote Scottish island to investigate the mysterious disappearance of a young girl. The islanders deny the girl's existence and appear to engage in bizarre, pagan rituals that unsettle him deeply. As he delves further, he uncovers unsettling evidence that suggests the islanders may have sinister plans tied to their ancient beliefs, and realizes he may be entangled in something far more disturbing than he imagined.