Mercy Falls (2023) Ending Explained – Carla’s Motive & The Cave Fight
Movie Details: Director: Ryan Hendrick | Runtime: 1h 43m | Release Date: 2023 | Star Rating: 2.5/5 Stars
Welcome to Knockout Horror. Today I am going to be explaining the ending to the British horror movie Mercy Falls from 2023. Although I didn’t hate this film, the movie feels stuck in the mud of its own predictability. The characters are thin, the plot is a bit silly in places, and the “heroine” is one of the most frustrating leads in recent memory.
That isn’t going to stop us from explaining the ending, though. Despite the plot being fairly straightforward, the motivations of our resident psycho, Carla, and the bizarre backstory of Rhona’s father deserve a bit of unpicking. Why did Carla go on a spree? And why is Rhona still mad about a horse from twenty years ago? Let’s get into it.
⚠️ Warning: Major spoilers follow below.
The Ending in Brief
The TL;DR: Carla is an escaped psychiatric patient and former military officer suffering from severe PTSD and homicidal tendencies. After systematically murdering Rhona’s friends, the two have a final showdown in a cave near Rhona’s father’s cabin. Rhona lures Carla into a trap, douses her in fuel, and sets her on fire. Rhona survives, finally “understanding” her father’s pragmatism through her own act of violence.
Why did Carla kill Andy? Carla used the guise of a “mercy kill” to hide her bloodlust. While Andy was badly injured, Carla slit his throat to prevent the group from calling for help, which would have exposed her status as a fugitive.
What was Carla’s backstory? A newspaper clipping reveals she is a wanted murderer who escaped from a mental facility. She was originally institutionalised after murdering two superior officers in Afghanistan who had assaulted a local woman.
The Resolution: Rhona wins the fight by using Carla’s own climbing gear and fuel against her. She walks out into the Scottish Highlands, the sole survivor of the hike, clutching a photo of her late father.
Good to Know: The title Mercy Falls refers to both the name of the location and the twisted “mercy” Carla bestows upon her victims by ending their lives.
Highlights
Mercy Falls (2023) Ending Explained
Let’s avoid the plot recap and get straight into explaining the ending. To understand why everyone ends up dead in the Scottish wilderness, we have to look at the group dynamic. We start with Rhona (Lauren Lyle), Heather (Layla Kirk), and Scott (James Watterson). They are joined by Donnie (Joe Rising) and the universally disliked Andy (Eoin Sweeney). The goal: find a hidden cabin left to Rhona by her estranged father.
The Trauma of the “Mercy Kill”
Rhona’s entire character arc is built on a foundation of resentment toward her father. When she was eight, they saw a horse that was mortally wounded and trapped. Instead of “saving” it (which was impossible), her father did the humane thing and put it out of its misery.
Rhona, however, decided that this made him a monster so she never spoke to him again. Though formerly close, they never spoke again after this and her father died alone in the middle of the woods… Nice!
This is honestly some of the weakest writing in Mercy Falls. We are supposed to empathise with Rhona, but it’s hard to invest in an adult woman who holds a decades-long grudge because her dad followed basic animal welfare protocols. However, this backstory sets the stage for Carla (Nicolette McKeown), the hitchhiker they pick up, who takes the concept of “mercy” and turns it into a bloodbath.
The “Horse Incident”: Mercy vs. Immaturity
The central trauma of Mercy Falls is Rhona’s lifelong hatred of her father for putting a dying horse out of its misery. To understand how ridiculous this is, we have to look at the ethics of animal welfare.
The Moral Reality: A horse trapped in the wild with a shattered limb or internal injuries faces a slow, agonising death from dehydration, shock, or predation. Rhona’s father performed a “mercy kill,” an act widely considered the only humane option in the wilderness when veterinary intervention is impossible. He didn’t kill the horse out of malice; he killed it to stop its suffering.
Rhona’s Reaction: While a child being upset by blood is normal, Rhona’s decision to remain estranged from her father for decades because of this is frankly absurd. It paints her as a character who values her own emotional comfort over the actual relief of an animal’s pain.
The Narrative Irony: The film tries to suggest that by killing Carla, Rhona finally “gets it”. But there’s a massive difference between killing an ailing animal to stop its pain and killing a psychopathic veteran in self-defense. By linking the two, the movie inadvertently makes Rhona look even more self-absorbed.
The Siren of the Loch
Before the bodies start piling up, the film makes a heavy-handed reference to Homer’s Odyssey. Scott reads the epic poem by the campfire, specifically focusing on the Sirens – mythological creatures that lure sailors to their doom with beautiful songs. This is mirrored in the scene where Carla and Donnie embrace under a freezing waterfall.
Donnie is the “sailor” lulled into a false sense of security by Carla’s beauty. Rhona watches this “tonsil tennis” in horror (the audio production here is a misophoniac’s nightmare, by the way), realising that Carla has effectively usurped her position in the group. Carla uses her sexuality and charm to divide the group, ensuring that when she starts killing, they are too fractured to fight back effectively.
The Catalyst: Heather’s Games and Andy’s Fate
Just as Rhona is jolted awake by yet another dream about that “stupid bloody horse incident”,further emphasising her role as a character who has fundamentally refused to mature over the last twenty years, she is thrust into a real-world parallel. The tension in the camp reaches a breaking point, not because of the wilderness, but because of the petty interpersonal drama Rhona’s friends brought with them.
Heather, in a display of truly twisted logic, reveals to Scott that she kissed Andy. Her goal wasn’t romance; she wanted to trigger Scott’s jealousy to prove he still cared enough to fight for her. She “won” her prize, but at a catastrophic cost. Scott emerges from his tent in a blind rage, confronting a shocked Andy who never realized he was merely a pawn in Heather’s emotional games.
When Scott pushes Andy, the situation turns from a scuffle into a medical nightmare. Andy swings a wild punch, Scott retaliates with a shove, and Andy falls backward, right onto a large, sharp branch that impales him through the leg.
Medical Reality: The Femoral Artery
The group panics as Andy begins to bleed profusely, and for good reason. The branch likely struck the femoral artery, the main blood vessel supplying the lower body.
When this artery is punctured or severed, the body can lose a life-threatening amount of blood in mere minutes. In the middle of nowhere, with no phone service and no medical supplies, Andy was effectively facing a death sentence.
This injury is the exact same one that claimed the life of NFL star Sean Taylor in 2007. It transformed a simple accident into a situation where Carla could justify her first “mercy” kill to the group, claiming she was simply ending his inevitable suffering.
The Descent into Spree Killing
Once Andy is dead, the group’s panic allows Carla to take total control. She manipulates them into a “cover-up”, telling them they are all complicit and will face jail time for Andy’s “accident”. This is the ultimate gaslighting tactic. By weighing Andy’s body down in the waterfall, the group is now legally tethered to a murderer. Now it’s time for a little more killing.
The deaths proceed with the logic of a typical slasher, albeit with some very questionable character choices:
- Donnie: He tries to be the hero by dropping a tree bridge into a ravine to block Carla. She simply appears behind him (teleporting, apparently) and buries a climbing axe in his neck.
- Heather: In the middle of being chased by a military-trained killer, Heather decides she needs a “private” piss 600 yards away from the group. Carla, who seemingly knows the bladder capacity of every character, is waiting there to hang her up like a macabre Christmas ornament.
- Scott: After reaching the cabin, Scott leaves his weapon behind to check a petrol generator. Carla stabs him and kisses him on the nose as he dies – a moment where Nicolette McKeown clearly enjoys the villainous camp of the role.
PTSD & Horror: The Villainy of Carla
Mercy Falls utilises a controversial trope: the “deranged veteran”. I absolutely hate this type of thing. Carla’s backstory involves witnessing war crimes in Afghanistan and seeking violent revenge on her superior officers. Something she was actually extremely justified in doing.
While the film attempts to give her a “sympathetic” origin, it ultimately portrays her PTSD as the source of a ruthless, spree-killing madness. This is a common, extremely offensive, horror shorthand that dates back to films like The First Blood or Combat Shock.
Carla isn’t just a survivor; she’s a predator who has completely abandoned her “rules of engagement” in favor of the primal thrill of the hunt.
The Final Showdown: Rhona’s “Home Alone” Trap
Rhona finally makes it to the cabin, but she realises she can’t outrun a soldier. She finds a photo of her father, which is supposed to be a moment of emotional clarity but feels unearned. She then sets up a trap in a nearby cave – lighting torches and luring Carla in with a flare.
The fight is visually striking, looking a bit like a 2000s music video with the red flare light (Snow Patrol, anyone?), but it’s fundamentally unrealistic. Rhona, who has shown zero survival skills up to this point, manages to douse Carla in fuel. With a flick of a light, Carla is incinerated. Rhona walks out of the cave, having finally “come to terms” with her father’s pragmatism by becoming a killer herself.
The Mercy Falls Body Count
The Highlands are beautiful, but they certainly aren’t safe. Here is who didn’t make it back to the car:
Andy: Accidentally impaled on a branch during a scuffle with Scott. While his leg injury was severe, Carla ensured he wouldn’t survive by slitting his throat under the guise of “mercy”. DEAD.
Donnie: Sacrificed himself to destroy the tree bridge and slow Carla down. He was hacked to death with a climbing axe for his trouble. DEAD.
Heather: Wandered off alone for a “private” bathroom break and was promptly hung from a tree by Carla. DEAD.
Scott: After reaching the cabin, he was ambushed by Carla while checking the generator. She stabbed him in the gut and kissed him as he expired. DEAD.
Carla: Lured into a cave by Rhona, doused in fuel, and incinerated with a flare. DEAD.
Frequently Asked Questions
Was Carla really putting Andy out of his misery?
While Carla claimed Andy would have suffered a slow death, her choice to slit his throat was a calculated move to gain control over the group. By forcing them to participate in a cover-up, she made them her accomplices, ensuring they wouldn’t turn her in to the police for her previous crimes.
What was Carla’s actual motive for killing the group?
Though she uses her PTSD as an excuse, Carla’s behavior, specifically her “Siren” like manipulation of Donnie and the sadistic way she torments Scott before his death, indicates she was hunting for pleasure. As an escaped psychiatric patient, she viewed the group as “prey” to test her military skills against in a live environment.
Who is the killer in Mercy Falls?
The killer is Carla, a hitchhiker who joins the group. She is later revealed to be an escaped psychiatric patient and former military officer who murdered her superiors in Afghanistan.
Why did Rhona hate her father in Mercy Falls?
Rhona witnessed her father perform a “mercy kill” on a trapped, dying horse when she was eight years old. Because she couldn’t understand the humane necessity of the act, she viewed him as a murderer and remained estranged from him until his death.
Does anyone survive Mercy Falls?
Rhona is the sole survivor of the group. Andy, Donnie, Heather, and Scott are all murdered by Carla. Carla herself is killed by Rhona in the final confrontation in the cave.
Is Mercy Falls based on a true story?
No, Mercy Falls is a fictional slasher movie. While it deals with real-world issues like PTSD and the isolation of the Scottish Highlands, the plot and characters are entirely invented for the screen.
Final Thoughts – Not With a Bang But With a Whimper
Mercy Falls is a movie that struggles to justify its own protagonist. Rhona is intolerable, and her “growth” into a survivor feels like a hollow victory given that her friends basically served as meat shields for her character development. Carla was the only interesting thing about this film, and had the movie ended with her winning, it might have actually left an impression. As it stands, it’s just another predictable trek through the woods. Thanks for reading!
Looking for more? If you enjoyed this breakdown, check out our review of Mercy Falls or browse our Horror Movie Lists.
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