Two fishermen capture a mermaid (Alexandra Bokova) and cut off her tail. When the fishermen are killed, the mermaid is taken by Dr. Beyer (Burt Culver), who wants to study her. He takes her to his practice, the Beyer Psychiatric Facility for Women, pretending that she's a mentally ill human. The mermaid suffers abuse from Dr. Beyer, but finds solidarity with the other patients, and with a ghost (Meggan Kaiser) that haunts the facility.
Mermaid Down contains examples of:
- Ambiguously Brown: Whatever ethnicity the Mermaid is, she certainly isn't Caucasian. Alexandra Bokova, the actress who plays the Mermaid, is a Russian-born mixed-race woman.
- Androcles' Lion: Sandra and some of the asylum patients storm Dr. Beyer's catamaran to rescue her. She then acts as The Cavalry, finishing him off and saving them from the sinking.
- Bedlam House: From the outside, the Beyer Facility looks like a pleasant suburban house. Inside, the patients are subjected to all manner of abuse, in addition to the indignities of institutional life. At one point Dr. Beyer has the windows nailed shut because the patients abused their "window privileges" by making an escape attempt.
- Beware of Vicious Dog: Dr. Beyer keeps a violently aggressive dog under the facility to which he occasionally feeds patients, including Linda.
- Big Bad: Dr. Beyer is a Mad Doctor and serial killer who uses his private rehab facility to procure victims.
- Binocular Shot: Used when Dr. Beyer spies on the fishermen from his boat.
- Bookcase Passage: A bookshelf on Dr. Beyer's boat turns into the door to the room where he dissects people alive if you pull on the lever disguised as the biography of H.H. Holmes.
- Broken Angel: When her tail is removed, the mermaid grows legs that look identical to those of a human. She says, through a sign language interpreter, that sailors used to take mermaids for their wives this way, and there are people today who are descended from merfolk and don't know it. Once she's in non-chlorinated water again, her tail grows back.
- Car Fu: Dr. Beyer is driving Sandra's car to work when he sees the mermaid, with her tail grown back, slowly pushing herself across the street in a wheelchair that's now too small for her. He accelerates and rams into her, sending her flying, to Sandra's shock.
- The Cavalry: Sandra and several mental health patients storm Dr. Beyer's boat to rescue the Mermaid in the climax. In return, the Mermaid helps them escape the boat when it sinks.
- Comforting Comforter: The ghost helps the mermaid into a wheelchair, since her legs aren't strong enough to walk on. Then she pulls several blankets over the shivering mermaid's legs.
- Covers Always Lie: The movie poster shown as the page image depicts a generic Mermaid with pale skin, black hair, and green scales facing away from the viewer, swimming in the ocean, posed as if she's hailing a fishing boat and a lighthouse. The Mermaid in the movie has olive-tan skin and brown hair (courtesy of Alexandra Bokova) and blue scales, her only interaction with a fishing boat is trying to escape from it, most of the movie takes place in a mental health clinic instead of the ocean, and no lighthouses appear in the movie.
- Creepy Basement: The facility's basement is unlit and flooded with about three feet of water. Dr. Beyer is told several times that it's a safety violation and he needs to have it blocked off, but he keeps it accessible so he can use it to punish patients.
- Cute Mute: The mermaid never has any lines in the movie, and is played by Alexandra Bokova, who is relatively attractive despite her hair being full of seaweed.
- Decoy Protagonist: The fishermen at the beginning of the film, trying to catch a mermaid to sate their curiosity, are killed by Dr. Beyer's men by the 20-minute mark. The mermaid becomes the new protagonist and Dr. Beyer becomes the Big Bad.
- Electric Torture: Dr. Beyer uses a taser to subdue the mermaid on several occasions.
- Electrified Bathtub: A patient trying to escape the Beyer Facility is killed when a pool of blood comes into contact with a live taser current.
- Establishing Character Moment: Dr. Beyer is introduced as observing a fishing boat capturing a mermaid, then sneaking aboard, acting diplomatic when the fishermen have him at gunpoint (stating an intent to buy the Mermaid off of them for up to a million dollars), and then murdering them when their backs are turned, introducing him as both a powerful and charismatic man and a Faux Affably Evil Mad Doctor with an interest in killing people.
- Gaslighting: It is heavily implied that the "patients" in the institution are being gaslit into thinking they are mentally ill.
- Fed to the Beast: Dr. Beyer keeps a dog in his basement to be the "Beast".Dr. Beyer: Who's gonna get a new squeaky toy tomorrow?
- Good Thing You Can Heal: Played for Body Horror- cut off a mermaid's tail and keep it on land, and it will grow legs instead until put back in non-chlorinated water again.
- Hope Spot: Dr. Beyer aims his tommy gun at Alex, only to run out of bullets, and for a moment it looks like Alex will survive, and "Ave Maria" begins playing. So Dr. Beyer shoots a taser into a part of the wall that blood is flowing down towards, and lets the electrical current do the rest.
- Impaled Palm: Sandra shoots Dr. Beyer right through the palm in an effort to protect the mermaid.
- Interspecies Romance: Mermaids learned sign language from pirates who fell in love with them, which explains how the Mermaid in this movie knows sign language. When one of the surviving asylum patients asks if any of them are descendants of one such couple, the mermaid simply points at one of them.
- Invisible to Normals: No one can see the ghost except the mermaid and a patient named June (Caroline Dunaway).
- Just Following Orders: The orderlies aren't actively malicious, but they also never question Dr. Beyer's orders, no matter how reprehensible. As one of them says, "I'm not the one with a PhD." They do turn on him once they realize he's a murderer.
- Mad Doctor: Dr. Beyer is secretly a serial killer.
- Mermaid Problem: Referenced. During his Attempted Rape, Dr. Beyer tries to cut the mermaid open to get access to her "fish parts."
- No Name Given: The mermaid and the ghost are never named.
- Not Quite Dead: Dr. Beyer, twice. The first time after he swallows a handful of fishhooks, interrupting the Casual Danger Dialogue of the patients trying to get off the sinking boat. The second time he emerges from the ocean in the very last shot of the film, only to be dragged underwater and killed off for good.
- Not-So-Imaginary Friend: Everyone thinks the ghost is June's imaginary friend. The staff tell the other patients not to encourage her delusions.
- Oh, Crap!:
- The mermaid has a protracted Oh Crap when her tail is cut off and she regrows legs.
- Linda finding a man-eating attack dog in a cellar under the basement, and the bones of his victims.
- Dr. Beyer's reaction to seeing the Mermaid having regrown her tail
- Sandra's reaction to Dr. Beyer's response to seeing the mermaid having regrown her tail.
- The patients' reactions to Dr. Beyer showing his true colors to them.
- Averted for when Sandra and some surviving asylum patients are stuck on a sinking ship, as they instead have Casual Danger Dialogue. Then played straight when Dr. Beyer is Not Quite Dead.
- Pixellation: When the mermaid takes off her clothes when she takes her first steps, the camera sometimes statics out when she's facing the camera. Averted otherwise, as the mermaid also has several full-frontal shots.
- Potty Emergency: As the patients are fleeing the institute, Alex (Shani Drake) says that she desperately has to pee and can't hold it any longer, and runs back to the bathroom. She walks in on Dr. Beyer as he's shooting patients who didn't get out on time. He electrocutes her to death.
- Psycho Psychologist: Dr. Beyer is a sadist who delights in tormenting his patients. He's also a serial killer.
- Punishment Box: Dr. Beyer has several tiny padded rooms in his basement where he locks the mermaid for telling the other patients their "secret." one wrong turn in this area leads to Dr. Beyer's man-eating attack dog in a hatch in the floor.
- Saw "Star Wars" Twenty-Seven Times: Charlotte (Eryn Rea) has been reading the romance novel Water Bound by Christine Feehan over and over again for the last two years.
- Seashell Bra: Referenced in the opening dialogue- one of the sailors asks if Mermaids have coconut bras, to which another replies that they don't.
- Shout-Out:
- The Big Bad Dr. Beyer has a biography of serial killer H.H. Holmes
that he uses as a lever to his Bookcase Passage. - The very last scene of the movie has Dr. Beyer get dragged under the water's surface to his final death, in a manner visually evocative of the opening scene of Jaws.
- The Big Bad Dr. Beyer has a biography of serial killer H.H. Holmes
- Skewed Priorities: Bordering on Too Dumb to Live—Alex's ill-timed Potty Emergency sees her break from escaping the institute with the other patients to run back inside it in search of a bathroom. Sure enough, she runs right into Dr. Beyer and is killed.
- Slasher Film: The movie becomes one once the mermaid is put in an institution, with Dr. Beyer in the role of the slasher.
- Soundtrack Dissonance: There are a lot of scenes where the music is surprisingly upbeat and hopeful for a slasher movie score.
- Stringy-Haired Ghost Girl: The mermaid often unintentionally resembles this, due to her tendency to crawl on all fours and have unkempt, messy hair. Averted for the actual ghost in this movie, who is benevolent and not unkempt.
- The Speechless: The mermaid can only vocalize in the form of grunts or shrieks. She also knows sign language, which her people learned long ago from pirates.
- Spiteful Spit: After the mermaid tells the other patients what she is, Reyna (Megan Therese Rippey), who thinks she's a faker, spits on her and says, "Fuck you, mermaid."
- Superhuman Trafficking: The fishermen want to sell the mermaid's upper body and tail separately for millions each.
- Token Good Teammate: Sandra is the one Nurse at Beyer's clinic who is unambiguously heroic, to the point of acting as a Team Mom for the patients. she's one of only two staff members who survive to the end credits.
- Unkempt Beauty: the Mermaid is never fully groomed, and always has messy hair (that, when she's in the sea, is full of seaweed).
- Wham Shot: The body found in the hull of Dr. Beyer's boat is the one that belongs to the Ghost that's been haunting the asylum.
- Wrongfully Committed: All of the patients are women who seem eccentric (or neurodivergent) at most, or supernaturally touched, not mentally ill. It's heavily implied that this is part of Dr. Beyer's M.O., gathering a bunch of victims into a convenient place at once.Patient: "Join the sorority, sister. None of us belong here."
