To Kill a Kingdom is a 2018 Young Adult novel by Alexandra Christio which is a loose adaption of The Little Mermaid.
The book follows the story of a war that is occurring between humans and sirens. Lira is the princess of the sirens and considered one of their most dangerous members, having taken the lives of seventeen princes. After an incident leads to her killing one of her own and letting a human get away, her abusive mother has her transformed into a human as a punishment. Lira is given till the winter solstice to give her mother Prince Elian's heart or remain a human forever.
Prince Elian is the most dangerous siren hunter in the world and fights an uphill battle to avenge his fallen friend who was killed by sirens. When he ends up rescuing Lira from drowning, she shows him a path to defeat sirenkind for good. The two end up working together while keeping their conflicting agendas secret.
To Kill a Kingdom provides examples of:
- Abusive Parents: The Siren Queen treats her daughter Lira awfully. She instills hatred and prejudice into her and abuses her hoping to mold her into a sociopath like herself.
- Big Bad: The wicked Queen of Sirens serves as the main antagonist. Her machinations and plans to wage war with humanity drive the plot of the novel.
- Brought Down to Normal: Lira's mother turns her into a human and steals her siren song as punishment for disobeying her.
- Fantastic Racism: Sirens and humans despise each other due to a centuries old war between them which led to the death of the Siren Goddess.
- Fiery Redhead: Lira has "hair as red as hellfire" and a personality to match.
- God Save Us from the Queen!: The Siren Queen is depicted as a genocidal psychopath who delights in hurting both humans and her own subjects. Her ultimate aim is to wipe out humanity itself.
- Kill All Humans: The Siren Queen's ultimate goal is to find an artifact from the siren's deceased goddess and use it to wipe out all of humanity in an act of genocide.
- Love Redeems: Lira starts off as a vicious Serial Killer of princes and has a distaste of humanity. She starts to fall in love with the human Prince Elian and eventually helps him to overthrow her bloodthirsty mother and create peace between sirens and humans.
- Mineral MacGuffin: The main characters spend most of the plot on a quest for the Second Eye of Keto, one of two powerful crystals said to be the eyes of the lost sea goddess.
- Monster/Slayer Romance: After being cursed by her mother to live as a human, siren princess Lira winds up on the ship of siren hunter Elian and they slowly end up falling for each other.
- Our Mermaids Are Different: Mermaids in this world are a distinct species from sirens. They are much more monstrous, animalistic, and fish-like.
- Our Sirens Are Different: Sirens are depicted as beautiful women with the lower body of a fish who use their songs to hypnotize and kill sailors.
- Princess Protagonist: Lira, the main character, is a mermaid princess.
- Sibling Murder: To try and eliminate any empathy in her daughter Lira, the Siren Queen tries to force Lira into killing her cousin (the Siren Queen's own niece). The Siren Queen's sister ends up sacrificing herself and allows Lira to kill her instead of her daughter, which the Queen allows and makes her giddy.
- Sirens Are Mermaids: Inverted, sirens and mermaids are both under the rule of the Sea Queen, but entirely separate species.
- Unscaled Merfolk: The Siren Queen has tentacles rather than a fishtail.
