Tidelands

Australian Netflix series Tidelands is set in the town of Orphelin Bay, childhood home of Calliope "Cal" McTeer (Charlotte Best). When Cal was a teenager she was arrested for murder and sent to prison, and the series opens 10 years later upon her release. Cal, who's an outcast, intends to return home only long enough to collect the money she should've inherited from her late father, but she falls right into the thick of Orphelin Bay's secrets.

The main secret of Orphelin Bay is its isolated commune L'Attente, which is ruled over by Adrielle (Elsa Pataky). The people of this commune are Tidelanders, who are eventually revealed be half-breeds, i.e. the offspring of mythical sirens with human men, and all of whom were abandoned by their siren mothers on shore as babies. Tidelanders have for generations had a working relationship with the regular humanfolk of Orphelin Bay, which is necessary for them to stay hidden from the wider world, but that very safety is threatened by their own queen, Adrielle, who has sights on something maybe-greater. Matters are made worse by Cal's return, which sets the two women on a collision course.

Although the show's single season ends in a place with the potential for more, a single season is all it has. That story is a house of cards that's falling apart card by card, with Cal's arrival being only one of the triggers that causes a chain reaction of bad things one after another. Most of the show's characters aren't nice people, or at the very least grey-morality hot messes who don't ask the right questions, which makes for drama.

Sirens are only briefly teased at, and their appearance is distinctly inhuman, with near-translucent white skin, matching long white hair and dark eyes. The Tidelanders all yearn to see these mothers they've never known, and Adrielle's promise to make this happen is one of the ways she keeps them in line. Tidelanders themselves look human, but they have some skills of the sirens, namely that they can breathe underwater, manipulate water (and by extension, blood), and use a siren call to hypnotize their victims. Cal in particular discovers that she has all these skills and more; although there are no swimming scenes, actress Charlotte Best pulls off some absolutely phenomenal acting of "breathing" underwater.