Based on a true story set in Australia around 1900, an eerie volcanic rock formation, millions of years old, becomes the spot of “A Picnic at Hanging Rock.” Privileged girls from Appleyard finishing school have an adventurous outing there. Taken by Miss McCraw (Vivean Gray), their chaperone, to the idyllic spot where they are warned to behave themselves, they find Hanging Rock hypnotic and enticing. Three girls, led by Miranda (Anne Lambert) climb into the mysterious crevices and abruptly disappear. One other girl is terrified by their climb and returns in hysterics, causing their chaperone to go also into the weird realm where she too disappears. Two local young men become obsessed with finding the girls, when the search party gives up. Their own dedication and sanity come under question. In the meantime, Miss Appleyard (Rachel Roberts) becomes driven to the brink of insanity herself by the disappearance of the girls and the ruination of her school from the scandal of the missing students.