Keeper of the Lost Cities

The series tells the story of Sophie Foster, a twelve-year-old high school senior with the ability to read minds. She lives in San Diego, California until a teenager with the same power, Fitz Vacker tracks her down. He tells her that she is an elf, and she must move to the Lost Cities, a hidden place where elves and other fantasy beings live. She is forced to leave her human family behind and stay with an Elvin couple, Grady and Edaline Ruewen, who later adopt her. She starts school at a school called Foxfire.

The series' reception was largely positive. Kirkus Reviews said of the first book: "wholesome shading to bland", but "well-stocked with exotic creatures and locales, plus an agreeable cast."[2] Booklist Reviews called it a "exciting start to a promising series."

On January 11, 2021, it was announced that Ben Affleck would be directing an adaptation of Keeper of the Lost Cities for Walt Disney Pictures. The release date and cast have not been announced.[3][4]

• Sophie Elizabeth Foster: The main protagonist of the Keeper of the Lost Cities series. She is a Telepath, Inflictor, Polyglot, Teleporter, and Enhancer. Her genes, sourced from two unknown elves, were tweaked by a rebel group called the Black Swan, giving her these powerful Elvin abilities. (Her genes were based on alicorn DNA.) One of her parents is later revealed to be the Councilor Oralie in Book 8, Legacy. She was raised by humans after her experimentation and brought back to the Lost Cities at age twelve to complete her education at the Foxfire Academy.
• Keefe Sencen: Sophie's close friend and current boyfriend, who is an Empath, allowing him to detect others' feelings. In Unlocked, he also becomes a Polyglot, capable of speaking all languages, and manifests an unnamed ability of emotional manipulation along with an unnamed ability allowing him to sense abilities.
• Fitzroy "Fitz" Avery Vacker: Sophie's close friend and first love interest/boyfriend. He is a highly skilled Telepath and becomes Sophie's Cognate, making them a close telepathic pair. After he and Sophie broke up, their Cognate relationship was damaged. He belongs to a prominent family of Elvin nobility.
• Dexter “Dex” Alvin Dizznee: Sophie’s best friend and a talented alchemist with Technopathy, the ability to manipulate technology, and her first kiss.
• Biana Amberly Vacker: Sophie’s friend and Fitz’s younger sister. She is a Vanisher, allowing her to turn invisible. She is often found sneaking around and listening in on people's conversations.
• Tam Dai Tong "Song": Sophie’s friend from Exillium, a school for banished and or "unruly" elves, who is a Shade, capable of manipulating shadows. Because of his status as a shade, he is rarely trusted by strangers.
• Linh Hai Tong "Song": Tam’s twin sister, also previously a student (a "Wayward") at Exillium, who can control water, which is called Hydrokinesis.
• Marella Adene Redek: Sophie's gossipy friend with a rare and illegal special ability, pyrokinesis, letting her summon fire and bend it to her will.
• Wylie Zoran Endal: The son of Prentice Endal who is a key member of the Black Swan. He is a Flasher and can sense and manipulate colors of light.
• Mr. Forkle: He is the leader of the Black Swan, and a fatherly parental figure to Sophie. When she was small, and still in the human world, he consumed ruckleberries, giving him a bloated look that reeked of socks. He signs his name as Errol Loki Forkle, or the acronym E.L.F. Secretly, he is two people. They were twins, but their parents were ashamed of having more than one child; and unusual occurence in the elvin world. As a result, they shared memories and identities. Sadly, one of the Forkles died, after being stabbed by Gethen, a Telepath in the Neverseen. Since his later revelation, Sophie has learned the truth about his twin identity.