On February 14, 1900 (Saint Valentine’s Day) a group of schoolgirls from Appleyard College near the township of Mount Macedon, Australia prepare giddily for a picnic at Hanging Rock. Mrs. Appleyard, the founder and headmistress of the school, advises the girls to be on their best behavior. Greta McCraw, the math teacher, and Mademoiselle Dianne de Poitiers, the French teacher, chaperone the trip. Mr. Ben Hussey, the owner of a local cab company, drives the group in a horse-drawn drag. He promises to have the group back no later than eight o’clock that evening. At the picnic grounds, the group enjoys food, tea, and an afternoon of dozing in the sun. Mr. Hussey notices that his watch has stopped—in order to make sure they’re back on time, he suggests that the group leave in about an hour. When a group of senior girls—the beautiful Miranda, the brainy Marion Quade, and the wealthy Irma Leopold—ask permission from Mademoiselle to explore the base of the rock, she allows them to go. The unpopular Edith Wharton begs the girls to take her along, and the kindhearted Miranda obliges her. As the girls leap over a creek to get to the base of the rock, they spot another group of picnickers—the wealthy Colonel Fitzhubert and his wife Mrs. Fitzhubert, their nephew Michael, and their coachman Albert Crundall. Michael (or Mike, as he likes to be called) notices Miranda’s beauty as he watches her jump the creek. At the base of the rock, Irma suggests they climb up to the first rise to take in the view. The girls follow Irma up and enjoy looking down at their schoolmates below. Edith says she isn’t feeling well and asks if they can turn back, but the older girls, as if in a trance, take off their boots and continue barefoot up the rock. At the next rise, the girls all stop and rest again. Edith dozes off and wakes to find the seniors pressing on. She calls and begs for them to come back, but when they do not turn around, Edith becomes filled with terror and flees down the mountain.
That night, Mrs. Appleyard grows concerned as eight o’clock comes and goes. Finally, around 10, the drag pulls up. Mademoiselle says something awful has happened and promptly faints. While Minnie, one of the maids, hurries Mademoiselle upstairs, Mr. Hussey informs Mrs. Appleyard that Miss McCraw, Miranda, Irma, and Marion have disappeared. The narrator of the book reproduces a clipping from Mr. Hussey’s report to the head of police, Constable Bumpher, stating that after Edith came screaming down the rock, the group noticed that Miss McCraw was missing, too. A search ensued, but as dark fell, the group decided to head back. In the days after the picnic, Mrs. Appleyard attempts to keep news of what has happened from getting out. Bumpher begins a search, enlisting the help of the Fitzhuberts, their coachman, several bloodhounds, and an Aboriginal Australian tracker—but the hunt turns up nothing. As the press seizes upon details of the disappearance, they begin showing up to the college and requesting statements from Mrs. Appleyard, who is busy trying to keep her traumatized students in line. Bumpher brings Edith back to the rock, hoping a visit will jog her memory. Though Edith still isn’t able to remember much of what happened up on the rock, she does recall that on her way down, she saw Miss McCraw, dressed in her underwear, headed up the other way. As Mrs. Appleyard fends off more and more members of the press, she realizes that the girls are not coming back—and that she must write letters to their wealthy, powerful parents informing them of what’s transpired.
Meanwhile, Mike remains perturbed by the disappearances. Albert, with whom he’s bonded over the last several days, tells him the girls are “bushed” by now—lost forever to the wilderness—but Mike is convinced that they are alive. Mike makes a plan to sneak away from Lake View, his aunt and uncle’s estate, the next morning and conduct his own search. Albert agrees to go with him. At dawn, the men ride out to the rock and head up the slopes. As night begins to fall, Albert suggests they head back, but Mike insists on staying the night. Albert returns to Lake View and lies to the worried Colonel about Mike’s whereabouts. At first light, Mike continues to make his way up the rock. He becomes terribly sleepy after a short while. He falls asleep and wakes in pain—he realizes that his head is bleeding. He passes out again, thinking of Miranda. The concerned Albert rides out to the rock and ascends again. He finds Mike unconscious on the ground near two large boulders. Albert runs for help. Doctor McKenzie accompanies Albert back to the rock, where they retrieve Mike and bring him home to Lake View. The next morning, Albert finds himself wondering what happened to Mike while he was on the rock. He slips into Mike’s room, retrieves his notebook, and finds a strange, incoherent note scrawled on one of the pages. Believing that the note is a clue, Albert alerts Colonel Fitzhubert, who calls a policeman, Jim Grant, and another physician, Doctor Cooling, and orders them to accompany Albert back to Hanging Rock. Though the doctor is dubious, Jim and Albert make their way up—and, near the boulders just ahead of where Mike was found, they discover an unconscious Irma Leopold. She is alive and unharmed. The men bring Irma back to Lake View, where the Fitzhuberts agree to shelter her while she recovers. Mike wakes up with no memory of what happened to him, so Albert pays a visit and explains everything. When Albert tells Mike that a girl was found alive, Mike asks which one—then becomes disappointed and withdrawn when he realizes that Irma, not Miranda, has made it home.
As the press sensationalizes the return of “MISSING HEIRESS” Irma Leopold, Mrs. Appleyard tries to keep the girls at the college calm—but as her frustration with the increasing public attention grows, she changes tack and begins disciplining them more seriously than ever before. She takes much of her ire out on the school’s youngest boarder, the orphaned Sara Waybourne, pulling Sara out of art class as retribution for her guardian’s late payment of tuition and ignoring Sara’s sadness over Miranda’s loss. Meanwhile, at Lake View, Mike and Irma have made full recoveries—though neither of them has any memories of the things they experienced on the rock. Mike and Irma strike up a friendship—one which Irma hopes will turn to romance—but as autumn approaches, Irma finds herself preparing to leave Lake View and rejoin her parents in Europe with no hint of resistance from Mike. Before leaving Australia, Irma pays one final visit to Appleyard College to gather her belongings and to bid goodbye to her fellow students. The visit is a disaster—when Irma steps into the girls’ gymnasium class, they grow hysterical and turn on her in a hateful, almost possessed mob. Irma flees, leaving Mademoiselle and Miss Lumley deeply disturbed by what they’ve seen—and determined to keep it from Mrs. Appleyard. Minnie fusses over Sara, who has seemed pale, ill, and withdrawn since Irma’s visit, refusing her meals and getting into frequent fights with the headmistresses. Miss Lumley summons her brother Reg to the college, begging him to take her away and help her find a new job. Together they take a train into Melbourne—but the hotel they choose to stay in for the night burns down, killing them both.
Mike is preparing to leave Lake View for the winter and travel through the Australian outback, starting in the north of the country. He invites Albert to join him, and Albert agrees, urging Mike to write to him with his itinerary as soon as he’s figured it out. As Albert drives Mike into town to make his train to Melbourne, an errand boy from a shop in town hands Albert a letter. Albert can’t read cursive so asks Mike to read the letter aloud to him. It is from Irma’s father, Mr. Leopold. The letter thanks Albert for his part in saving Irma’s life, and the envelope contains a cheque for 1,000 pounds—more money than Albert has ever had in his life. After dropping Mike off at the station, Albert returns home and begins dreaming of traveling the countryside with his friend.
On the last Sunday before the Easter holiday, Mrs. Appleyard informs Minnie that Sara’s guardian, Mr. Cosgrove, will be coming to collect her later that day. Mrs. Appleyard insists that Minnie, who usually answers the door, ignore the bell and let Mrs. Appleyard handle the interaction. Mrs. Appleyard looks pale and strange, but she offers Minnie a bonus on her wedding day—Minnie and Tom, the groom and stable boy, are soon getting married—and Minnie agrees. Later that afternoon, Mademoiselle, who has been concerned about Sara, visits the headmistress’s office to talk to her about the girl—but a pale-looking Mrs. Appleyard informs her that Sara has left for the term. That evening, as Mademoiselle helps one of the maids clean out Sara and Miranda’s now-empty room, she sees that Sara has left behind her most prized possession: a miniature portrait of Miranda. Knowing the girl would never willingly leave the picture behind, Mademoiselle writes a letter to Bumpher expressing her suspicions that something has gone terribly wrong. That night, while everyone else is asleep, Mrs. Appleyard rises from bed and goes into Sara’s room, where she has a flashback of standing over the screaming girl. She hurries back to bed.
On Thursday, Mrs. Appleyard receives a letter from Sara’s guardian stating that he is coming to collect her from school in three days’ time. The next day, while planting flowers behind the school, Mr. Whitehead, the gardener, notices a terrible smell coming from a hydrangea bed. He examines the bush more closely and finds that several stems are crushed. As he cuts the ruined flowers away, he sees something in the hedge: it is the body of Sara Waybourne. Though her face is crushed in beyond recognition, the gardener knows from the petite frame just who it is. Mr. Whitehead informs Mrs. Appleyard of what he’s found. She goes pale and orders him to ready a horse and buggy to take her to the police station in town. Once there, she orders him to drop her off and leave her. After Whitehead departs, Mrs. Appleyard pays a visit to Ben Hussey and asks him to drive her out toward Hanging Rock, claiming to have gotten some bad news from friends who live out near the mount. Hussey drives her out to a remote house, where she asks him, just as she asked Whitehead, to drop her and leave her. Mrs. Appleyard walks the rest of the way to Hanging Rock, climbs to the summit, and has a vision of the dead Sara Waybourne. Terrified, Mrs. Appleyard flings herself off the mount, falling to her death on the rocks below. A clipping from a Melbourne newspaper dated February 14, 1913 reveals that Appleyard College burned to the ground in 1901, while the disappearances at Hanging Rock remain unsolved.
