History Literature / IntoTheDrowningDeep

* BlandNameProduct: In-universe visual example: Olivia dresses ''almost'' exactly like Emma Frost of ''Franchise/XMen'' fame, close enough that fans of her show can see the resemblance but not so close that [[Creator/MarvelComics Marvel]]/Creator/{{Disney}} can sue the studio.

* DisabledMeansHelpless: How people tend to view the Wilson twins. This is lampshaded by Heather in that she knows companies will often actively try to find loopholes to avoid hiring her and her sister due to their deafness, viewing them as distractions at best, liabilities at worst.

** Olivia, an autistic lesbian.

* AlluringAnglerfish: While they are compared to other animals as well, the sirens are similar in many ways to anglerfish. They live in the darkest depths of the ocean, they use a variety of methods, including bioluminescence, to lure in prey, [[spoiler: and have BizarreSexualDimorphism.]]

* OurMonstersAreDifferent: Again, the sirens are not like the conventionally modern depictions of mermaids. They're terrifying deep-sea creatures that can also survive above the water's surface for extensive periods of time.

* MadScientist: Well, they aren’t mad, per say. But there are plenty of scientists that have a wide range of dedicated studies and specialities in marine biology, oceanography, and more. Dr. Toth may come closest to this description, as she’s seen as a "sirenologist" by the community at large due to her advocation for the existence of sirens/mermaids.

* HidingtheHandicap: Theo can hide his limp and his crippling agony to a certain degree, but only if he takes his medication regularly.

* NoBisexuals: Tory in her internal monologue mentions encountering this attitude before, thinking of how people sometimes assumed she's just confused or indecisive over her sexuality, though it isn't the case and Tori's actually bisexual.

* NoBisexuals: Tory in her internal monologue mentions encountering this attitude before, thinking of how people sometimes assumed she's just confused or indecisive over her sexuality, though it isn't the case and she's just bisexual.

** Jillian is a woman of Caucasian and Native Hawaiian ancestry. This goes as well for her daughter Lani with her estranged husband Theo, who's white, as well.
** Heather and Holly, identical deaf twin sisters.

* UnholyMatrimony: Jacques and Michi are a pair of murderous {{Egomaniac Hunter}}s and love each other as the only person in the world who can understand each other. The narration notes that Michi's influence is the only reason Jacques is a big game hunter instead of a SerialKiller, and [[spoiler:her death leaves him fatally unhinged.]]

* MeanBoss: Dr. Lyons, the scientist in charge of overseeing Jason, hands down. He essentially forces all his students to do the lab work, write all of his papers, and to run all the errands. Granted, this is generally what lab assistants are expected to do—but Dr. Lyons is especially an asshole about it and takes things to a whole new level. To hammer home how big an asshole he is, he isn’t above [[spoiler: stealing the credit of any worthwhile research his students conduct and publishing it as his own.]]

*** This callousness could further lend to the tragedy of Jason’s death. He had taken the little creatures living in the siren’s “hair” and performed the makeshift necropsy in his cabin rather than in a lab setting. Indirectly, one could even argue Dr. Lyons was the reason Jason had died so pointlessly.

* OurMermaidsAreDifferent: Here they are a unique species of predatory amphibians with eel-like tails, [[BioluminescenceIsCool bioluminescent hair]], [[VoiceChangeling the ability to perfectly mimic any sound they hear]], and [[spoiler: [[BizarreSexualDimorphism sexual dimorphism similar to anglerfish.]]]]

* ActionSurvivor: Tory, Dr. Toth.

* EvilCripple: While Theo isn’t necessarily evil, but he is still seen as a corporate crony. He even straight-up admits the first night to everyone that he is a spy for the Imagine Network.

* HideYourGays: Averted, with Tory being the main example.

* UsefulNotes/SignedLanguage: How Heather and Hollie, the Wilson twins, communicate as they were both born deaf. Their older sister Hallie Wilson often acts as their interpreter, a sort of liaison between them and other people. She’ll also sign for them when someone else is speaking such as on a podium or stage. They don’t necessarily need her for face-to-face interactions. [[spoiler: The sirens also have their own form of sign language. A live siren specimen, after having being captured, begins a rudimentary exchange of signs with a character so the two species can open the beginnings of a line of communication.]]

* UsefulNotes/SignedLanguage: Three of the characters are fluent in American Signed Language, one of whom is an expert brought in to study the sirens' own signed language.

* SignedLanguage: How Heather and Hollie, the Wilson twins, communicate as they were both born deaf. Their older sister Hallie Wilson often acts as their interpreter, a sort of liaison between them and other people. She’ll also sign for them when someone else is speaking such as on a podium or stage. They don’t necessarily need her for face-to-face interactions.

* SirensAreMermaids: The mermaids here are capable of perfectly mimicking any sound they hear, such as whale song and human speech, in order to learn prey in. Eventually, they are designated as sirens because mermaid implies they are all female. The study of mermaids is also known as sirenology.