Warning: SPOILERS ahead for Mercy Black

Netflix and Blumhouse Productions surprised audiences with the (US-only) release of horror movie Mercy Black, and we’re here to break down its chilling ending. Written and directed by Owen Egerton, the film stars Daniella Pineda as Marina Hess, a young woman who has been institutionalized ever since a violent episode in her childhood. Upon finally being released from the psychiatric facility as an adult, Marina finds herself once again plagued by the terrifying figure from her childhood: an entity called Mercy Black, who demands human sacrifices so she can become flesh and blood.

Mercy Black appears to be based on the true story of the Slender Man stabbing case of 2014, in which two twelve year-old girls lured their friend out to the woods and then stabbed her nineteen times as a tribute to the viral internet horror figure. Fortunately their victim survived, and the two assailants were found not guilty by reason of insanity and sent to mental health institutions - just like Marina and Rebecca in Mercy Black.

Much of the film is built around the question of whether or not Mercy Black is real, or whether she’s just the figment of two young girls’ overactive imaginations. The twists and turns of the plot keep audiences guessing right up to the end, and even by the time the credits roll there are questions left unanswered about Mercy Black’s true nature.

  • This Page: The Lily Twist and Mercy Black’s Origins Page 2: The Real Meaning of Mercy Black Explained

Lily’s Surprise Return Explained

The major twist of Mercy Black is that Lily, the girl that Marina and Rebecca sacrificed to Mercy Black as children, didn’t die. She’s actually been in the movie all along, as the friendly librarian who takes an interest in Bryce. Lily has been deliberately grooming Bryce as a new worshipper for Mercy, by pretending not to have heard of Mercy and encouraging Bryce to look her up on the internet. This set in motion Bryce’s own belief in Mercy, leading to him seeing her in the air vent in his bedroom and eventually attempting to murder his “friend” Sam.

As Dr. Ward explains, Lily dropped off the grid as an adult and changed her name so that Alice wouldn’t know the nice librarian who was keeping an eye on her son was actually the girl that Marina almost murdered. A flashback towards the end of the movie reveals that Lily wasn’t just an unsuspecting victim, but that she made her own promise to Mercy Black when they were children. Throughout the movie Lily has been trying to manipulate Marina into believing in Mercy again so that she can complete her sacrifice of Lily. Finally, Lily resorts to threatening Bryce’s life so that Marina will be forced to kill her - but Marina ultimately refuses. Lily gets her wish, however, when Bryce finishes the sacrifice.

Mercy Black’s Origins & How She Became Real

Early on in Mercy Black, there are indications that the titular monster might have been something older that was simply discovered by Rebecca and Marina. There are references to “a house you cannot see” and “a book you cannot read,” both of which conjure up images of a witch’s house in the woods and a book of spells. However, after finding a map in Rebecca’s room, Marina is able to retrace their steps and find the truth about Mercy Black’s origins. The “house you cannot see” is actually a nuclear bunker in the woods, whose entrance was hidden by leaves, and the “book you cannot read” is actually a book called Greek Language For Beginners. Lily reveals her true identity and says that she did terrible things to people to make Marina believe in Mercy again (indicating that it was actually Lily who killed Will).

At first Marina is relieved, believing that her discovery proves that Mercy Black was never real and was only ever a figment of her and Rebecca’s imagination that got out of hand. However, while some manifestations of Mercy Black could be written off as hallucinations or perhaps Lily wearing a costume, it’s pretty clear by the end of the movie that this supernatural being does exist, despite being invented by Rebecca and Marina as children. The best explanation for this is that Rebecca and Marina were practising a kind of witchcraft, complete with careful rituals and promises of sacrifice to Mercy Black. Their belief and worship either imbued Mercy Black with life, or invited some kind of dark spirit to inhabit the figure that they made.

The nature of Mercy Black is that her crude form is not meant to be her final form. Her followers must make human sacrifices and gift body parts to her in exchange for having their wishes granted. For example, Rebecca wished to be rid of her abusive father, so she put his hunting gloves on Mercy Black as her “promise” and then cut off Lily’s finger as a tribute. It’s indicated that Rebecca got her wish, since her father died before she came home from the psychiatric facility. Bryce also makes a sacrifice by stabbing Lily in the eye, and after he does this we see Lily’s eye in Mercy Black’s face. With each body part sacrificed, Mercy comes a little closer to being flesh and blood.

Page 2: The Real Meaning of Mercy Black Explained

The Real Meaning of Mercy Black Explained

The central theme of Mercy Black is that ideas themselves can be dangerous. Although Mercy Black started out as the invention of two little girls, the media coverage of Lily’s stabbing meant that Mercy went viral on the internet, inspiring copycat killings all over the world. This is where the real-world inspiration for Mercy Black becomes particularly relevant, because Slender Man is not an ancient being from legend. He’s a creepypasta, created in the internet age, with many people making contributions to his folklore. Nonetheless, Slender Man became real enough to inspire the 2014 stabbing incident, which shows the kind of power that even a recently made-up boogeyman can have.

Most of the horrible acts committed in Mercy Black aren’t done by Mercy himself, but by people making “promises” to her: first Rebecca and Marina stabbing Lily, then Bryce tricking his mother into almost strangling Sam, then Lily murdering Dr. Ward, and finally Bryce completing Lily’s sacrifice. This maintains the mystery of whether or not Mercy Black is “real” until the very end of the movie, but it also drives home the point that the most dangerous thing about Mercy is the people in believe in her. Belief fuels Mercy’s ability to physically manifest, so people who don’t believe in her can’t see her.

Mercy Black is part of a broader recent trend in horror towards digital folklore, most aptly represented by Syfy’s horror anthology series Channel Zero. Each season of Channel Zero is based on a creepypasta - from “Candle Cove,” a story about a strange children’s television program that people remember watching as children, to “No-End House,” in which people visit a haunted house that keeps haunting them even after they’ve left. The final season, “Dream Door,” has a similar premise to Mercy Black: in it, a woman rediscovers an imaginary friend she created as a child, who now has a murderous appetite.

What all of these stories have in common is that they don’t really need a firm explanation, and they defy the more traditional idea in horror that monsters need to come from somewhere, whether they’re ghosts, demons, or witches. In Mercy Black, the only thing required to bring Mercy into existence is that people believe in her - and that’s what makes her so dangerous.

More: The Best Horror Movies On Netflix