The Blackcoat’s Daughter Explained: Murder, Mystery, and Demonic Possession

With Anthony Perkins for a father, it’s no surprise that Oz Perkins would grow up to direct horror movies. His debut, The Blackcoat’s Daughter, is a deeply affecting and unsettling film that uses its wintery setting to underscore the cold relationships between characters. The movie follows three young women who all have a connection to an all-girls Catholic school. The film contains murder, mystery, demonic possession, and an emotionally charged conclusion that is a lot to unpack.

Introducting Katherine

In trying to make sense of the film’s layers, it’s important to have a firm grasp of the main characters. Katherine (Kiernan Shipka) is a lonely student at Bramford Academy who is convinced her parents are dead. In her first scene, she dreams of a cloaked figure she refers to as “Daddy,” who shows her a smashed car. Kathrine cries out, “Mom.”

Katherine stays at Bramdford over winter break because her parents never arrive to pick her up, again implying that perhaps they are dead. It’s also clear that Katherine doesn’t have many if any, friends at school. Her sense of isolation is reinforced by Perkins’ opening shot of a snowy, mid-winter landscape, just before he cuts to Katherine’s disturbing dream.

Introducting Rose

Rose (Lucy Boynton) is another Bramford student. She also stays over winter break. However, she does so because she doesn’t want to go home, so she never tells her parents to pick her up. Instead, she spends most of her nights sneaking out and hanging with her boyfriend. Further, Rose is more rebellious, often depicted smoking in her earliest scenes and having a conversation with a friend about whether she’s pregnant.

Rose eventually befriends Katherine (sort of) or at least shows concern when Katherine starts exhibiting strange symptoms (more on that soon). Because there are no other girls at the school during winter break, they really have no choice but to interact. This includes a disturbing dinner scene with two nuns much later in the film.

Introducing Joan

Joan, played by Emma Roberts, is an escaped mental patient, though it’s unclear why she fled the hospital, at least initially. Eventually, she meets grieving parents, Bill (James Remar) and Linda (Lauren Holly). When they offer to drive her to the next town over from Bramford, it’s clear they have some connection to the academy. They have a faded Bramford bumper sticker.

At first, Joan’s past and identity are shrouded in mystery. As the film progresses, however, more and more clues indicate that she also has some connection to the academy. This reveals itself slowly as these dueling narratives slowly unwind.

Katherine’s Possession

Courtesy of Eggplant Picture and Sound

From the get-go, beyond the strange opening dream sequence, something’s off about Katherine. In an early scene in the headmaster’s office, Katherine spaces out and smiles for seemingly no reason. Later, Rose hears strange voices coming through the vents. She follows them and spots Katherine bowing in the boiler room. Talk about creepy! In the closing 30 minutes, Katherine keeps receiving phone calls from a strange voice, telling her that her parents are dead and that she needs to stay with him. She also refuses to say grace when she and Rose dine with two nuns, and she vomits all over the food.

Ultimately, Katherine murders the nuns and severs their heads. Then, she kills Rose by stabbing her several times. As she pulls Rose’s corpse by the hair, the camera cuts away. It implies that she’s going to behead Rose, too. She then takes the three heads to the boiler room as a sacrifice of sorts to the demon. When a cop finds her, she repeats, “Hail Satan” several times, her voice dropping to a growl before he shoots her. Eventually, she’s institutionalized.

Bill and Lauren’s Daughter

Despite not knowing a thing about her, Bill treats Joan with love and respect, telling her several times that she reminds him of his daughter. When they have dinner, he pulls out a picture of his dead daughter, who just so happened to be Rose. This causes Joan to leave the table and flee to the bathroom. There, she has a flashback of strangling a woman and taking her ID, renaming herself Joan.

It’s important to mention that Bill tells Joan that his daughter would have been her age. Later, while in the car, Lauren tells Joan that her husband tells every young woman that they look like Rose and that he speaks of her as if she’s still alive. He refuses to admit she was murdered. Bill and Lauren process grief differently, and this has driven a wedge between them. Lauren specifically offers no affection towards her husband and instead seems frustrated that he won’t acknowledge the truth about Rose’s murder.

Joan Is Katherine

The reveal regarding Rose’s murder and Joan’s reaction to it is the first major indicators that Joan murdered Rose and she is indeed Katherine. Thus, Joan’s narrative occurs in the present day, while the narrative following Rose and Katherine occurred in the past. Joan escaped the mental hospital nearly a decade after killing Rose and the nuns at Bramford.

Additionally, near the end of the film, Katherine looks more and more like a younger Joan, with the same blonde hair and similar facial expressions. In fact, it’s uncanny how much Shipka looks like a younger version of Roberts at times. Ultimately, Joan murders Lauren and Bill by stabbing them and beheading them. She then stuffs their heads in a suitcase and returns to Bramford to summon the demon.

The Ending Explained and Joan’s Return to Bramford

The Blackcoats Daughter Explained

The film concludes by showing what happened to Katherine before she became Joan and then Joan’s ultimate failure to reconnect with the demon after returning to Bramford. The headmaster performs an exorcism on Katherine shortly after she kills the nuns and Rose. She pleads with the demon not to leave her. It’s shown in the corner of the room, a shadowy, horned being. Yet, because the demon is separated from her body, it indicates that the exorcism worked.

When Joan returns to Bramford nearly a decade later, she goes back to the boiler room where it all started. She offers Bill and Lauren’s heads as a sacrifice, but the demon doesn’t return. The boiler is cold. The film concludes with Joan walking down the street, having left the school. She wails and cries. Her final reaction can be read a few ways. She desperately wanted the demon to return to ease her loneliness. When it doesn’t materialize, she feels hopeless. The other possibility is that she realized she killed Lauren and Bill for nothing and the sacrifice was in vain, especially after Bill was so nice to her. It’s possible she actually feels remorse for her actions.

The Blackcoat’s Daughter is a haunting, mesmerizing film that shows just how well Perkins can use cinematography and setting to establish mood, which is apparent in his subsequent films, too. It’s also a story about grief and loneliness so immense that a young woman turns to Satanism as a way to ease her pain. At first, the narratives may seem confusing, but upon a rewatch or two, it’s evident that Perkins sprinkled several clues indicating that Joan is Katherine, and her only real friend is a demon.