'What Lies Below,' the latest soapy thriller confusing Netflix viewers, is a shallow mishmash of horror tropes

• "What Lies Below" has been a top-ten trending movie since it came to Netflix in early April.
• The erotic-thriller aspects make it an enjoyable enough watch, purely for the suspense.
• But the muddled sci-fi elements - and bizarre, rushed ending - make the movie an overall let-down.

Warning: This review contains major spoilers for "What Lies Below."

Braden R. Duemmler's psychosexual aquatic horror film, "What Lies Below," is a slow burn, but not the kind that actually promises the reward for hanging in there at the end, and that might be its biggest flaw.

While "American Beauty" breakout star Mena Suvari and newcomer Ema Horvath deliver convincing performances as the mother and daughter duo in the film's opening sequence, it's not enough to sustain the utter strangeness that ensues.

It all begins when a cheerful Michelle (Suvari) picks up teenage daughter Liberty (Horvath) - err, "babygirl" - from archaeology camp. They head to the family lake house in the Adirondacks where, much to Liberty's dismay, Michelle's allegedly perfect boyfriend John (Trey Tucker) awaits their arrival. Liberty's frustration quickly evolves into awe after she witnesses his abs glistening in the sun as he dramatically emerges from his casual dip in the lake - in a speedo.

"I know. I'm riding him constantly," Michelle quips in response to her daughter's gawking, an immediate, jarring indicator of the dynamic we're about to see play out.

Liberty can't help but feel attracted to John's good looks and smarts - after all, he's studying freshwater creatures so that he can heroically aid their survival in saltwater conditions, which makes for an intriguing movie premise.

What's hot: Trey Tucker as John Smith, the handsomely sculpted 'aquatic geneticist' boyfriend, and the backdrop of lust and desire his character evokes

The psychosexual aspect of this film's genre works, spearheaded by Tucker's performance.

If you classify "What Lies Below" as purely an erotic thriller and disregard the sci-fi elements that randomly appear in the story, it might just pass the test. There's plenty of illicit romance and sexual fantasizing to go around, starting with the most obvious chemistry between Michelle and John, which then matures into a forbidden love triangle with sinister John at the center.

Liberty is presented as a quiet, socially-awkward teenager with a nerdy passion for archaeology. Her mom, on the other hand, has fully embraced her sexuality and has no problem making that abundantly clear to Liberty, who accepts Michelle's openly hot and heavy relationship with the hesitancy and caution that would make sense for a developing 16-year-old girl.

Still, from the moment John gifts Liberty a Navajo fertility bracelet upon their first meeting, shrewdly capitalizing off of Liberty's interest in historic tokens, a slightly-weird, definitely-creepy vibe is established between them. What follows is a bizarrely sensual hand rest on Liberty's shoulder, lingering looks, and a scene in which Liberty masturbates while touching that same shoulder, only to be cut short by the deafening sounds of Michelle's shrieks as she and John have sex in the neighboring bedroom.

By this point in the movie, it comes as no surprise when Liberty tries to sneak up on the two of them engaging in such activity, undoubtedly intrigued. Meanwhile, it seems that John wants this effect, and is trying to send a message to Liberty that she's not too far off from joining her mom as the object of his desire.

What's not: The ending

John's freakish, seductive aura is the driving force of intrigue here, which reaches another level of extreme when Liberty catches him drinking his own sweat from his wrung out gym shirt.

In an even more disturbing scene, Liberty gets her period while the two of them are on a boat searching for lake creatures - John's idea of bonding. He then proceeds to shove a shirt down there to supposedly prevent the blood from staining her dress, only to then lick his fingers doused in Liberty's period blood. He's so turned on by this that he creeps on Liberty showering so that he can smell her soiled clothing, in an extremely menacing turn of events.

Not to mention this whole time Michelle is bed-ridden with a stomach illness that doesn't seem to overly concern John. As a viewer, I'm thinking - what's his deal? And so is Liberty, who is now fully convinced that the stranger she initially had reservations about is far more devilish than just a weird guy with a hot body.

Unfortunately for Michelle, this realization comes too late despite her daughter's fair amount of warnings. Perhaps love is truly blinding. Next thing you know, Michelle is half-conscious while submerged in a water tank in John's underground aquarium, connected to a bunch of tubes as he attempts to force her to give birth to some aquatic organism.

The ending that is crammed into the last twenty minutes hardly does much in the way of explaining these circumstances, or rather, it does so in what feels like a cheap, rushed way that lacks the meaning it could.

It turns out that John is part-monster with clawed feet, part-aquatic creature with scales on his back, and part-mystical demon with the ability to cough up a neon blob that impregnates his receiver with more of his kind - his ultimate plan for Michelle and Liberty.

Sure, we get hints of these supernatural qualities when Liberty sees John walking into the lake in the dead of night, summoned by an orange hue, and most evidently when John's body partially turns into a scaly fish specimen as he's on top of Michelle in bed at the end, another unfortunate viewing Liberty was privy to.

The conclusion is frustratingly lackluster, leaving us with the only plausible judgment that John is not fully human and performs "scientific" experiments on female bodies in an effort to perpetuate his kind, whatever that may be.

Liberty winds up being captured in a water-filled glass vessel built into the wall of the basement, where she joins an array of other trapped young girls, who are presumably dead.

Michelle, nowhere to be found, is assumed to be discarded as she's not young enough for his goal of reproducing - which explains John's fury when Liberty exposes her mom's real age.

Bottom line: Watch it purely for the suspense, if you don't mind being disappointed at the end

While "What Lies Below" could've worked as a spinoff in the vein of "Dirty John," it sadly missed the mark.

The character of John (whose full name is John Smith, perhaps alluding to the idea that he's just a template of a real person) is presented as an intruder in Liberty's life and an obstacle in her relationship with her mom.

His ultimate intentions underlying his ominous behavior are chalked up to a supernatural explanation, which is hardly the deep dive the film could've taken.

The bulk of "What Lies Below" is captivating, yes, but the what-just-happened ending makes you question whether it was worth your patience all along.

Grade: C+

"What Lies Below" is currently streaming on Netflix.