2012’s Keeper of the Lost Cities by Shannon Messenger is a fantasy-adventure coming-of-age novel for advanced middle-grade readers. Brilliant young Sophie Foster discovers she’s not human but an elf with psychic powers. She must leave the human realm, study at an academy for elf prodigies, and try to understand the strange memories that haunt her and may put her life in peril.

Since the book’s publication, Messenger has released several sequels, and the series reached the New York Times bestseller list. A film adaptation is in development. Messenger also writes the young-adult series Sky Fall.

The ebook version of the 2012 edition forms the basis for this study guide.

Plot Summary

Sophie Foster is a brilliant 12-year-old high-school senior who can hear other people’s thoughts. On a trip with her class to a natural history museum in San Diego, she meets Fitz, a tall, handsome 15-year-old boy with glittery-blue eyes who also has telepathic powers. Overwhelmed to meet someone like her, Sophie runs, but he follows and tells her she’s not a human but an elf, a much superior being. He and other elves have been searching for her for years.

To prove it, he takes Sophie’s hand, aims a crystal-tipped wand at a beam of sunlight, and travels with her on the light beam across the world to a hidden city, Eternalia, lush and beautiful with jewel-like buildings, one of the lost cities of human myth. Fitz then takes her to Lumenaria, another lost city that’s the meeting place for goblins, gnomes, dwarves, and other intelligent beings. Humans once belonged to their federation, but they tried to conquer all of it and were banned.

Back home, Sophie realizes that her family isn’t related to her. The next day, Fitz takes her to Everglen, his family estate. His father, Alden, presents her to three members of the elf Council, who consider Sophie for admission to their elite academy, Foxfire. Though still new at using her abilities, she reads the mind of skeptical Councillor Bronte, makes glasses rise from a table, lifts Bronte into the air, and foils his attempt to read her thoughts. He doesn’t trust her for her impenetrable mind and her unusual upbringing among humans, but the other two Councillors favor her.

To settle the issue, Sophie travels with Fitz and Alden to Atlantis, one of the cities humans believe is lost. There, telepathy expert Quinlin Sonden declares that Sophie’s mind block is impenetrable. They also confirm that her DNA matches the elves’ records.

Sophie’s no longer safe on the human world, so she goes home to say a tearful goodbye to her family, whose minds are then cleansed of all memory of her.

She meets her new elf family, Grady and Edaline, who lost a daughter tragically and still grieve. They run a nature preserve that includes mammoths and dinosaurs. They’re kind to Sophie and provide her with a wonderful home.

Sophie begins at Foxfire, where she must learn to control wind and lightning, memorize thousands of astronomical objects, and channel her telepathic abilities. Her telepathy Mentor, Tiergan, can’t penetrate her mind block. She’s good at classes requiring memorization, but she’s terrible at moving objects with her thoughts. She blows up a serum in Alchemy class. One student, Dex, resents the elvin noble class for its snobbery, and he despises Alden’s family, but he likes Sophie, and they become friends.

In physical education class, the students play Splotch, pushing paintballs at each other with their minds. Sophie makes it to the final against Fitz: Their battle is so intense that both are hurled backward and knocked out. Sophie wins, but it’s a mystery how she did it without training.

Fitz’s beautiful sister, Biana, seems to dislike Sophie, but one day she asks to be Sophie’s friend, and they hit it off. Sophie spends more time at their home, where she meets Fitz’s mother, Della, who can appear and disappear at will. She also makes friends with Fitz’s friend Keefe, a mischievous boy who loves to tease Sophie but also admires her. Meanwhile, Grady and Edaline bond with Sophie, who finally feels like she has a home.

The upcoming midterms rattle her, and she breaks a law by reading her alchemy teacher’s mind and learning what will be on the test. Stricken with guilt, she confesses to Alden. Principal Alina gives her several weeks’ detention. Sophie still manages to pass all her classes, some by a hair’s breadth.

On a class assignment to gather starlight, Sophie plays a sudden hunch and collects light from a star, Elementine, but the light, Quintessence, is forbidden. Sophie faces a tribunal where she explains she had no idea about Quintessence; they let her off, but she and Alden realize that her mind contains implanted information. Bits and pieces of it begin to emerge in her memories. Alden has her keep a log of these thoughts.

At the nature preserve, Grady tries to calm an angry eagle-sized bird. Sophie reads the bird’s mind and learns it needs fire, so she ignites a pile of leaves, and the bird, a flareadon that requires extreme heat, dives into it, warming itself. Edaline, whose daughter died in a house fire, is so shocked by this incident that she can no longer bear to adopt Sophie. Sophie feels crushed, but Alden offers to adopt her, and her resentment cools. 

Sophie receives several cryptic messages and small, decorative items. At one point, she learns that her human family is endangered by one of the many fires that suddenly erupted around the world. The messages and items hint that she has the power to stop the fires, which the elf Council refuses to acknowledge. Sophie transports the flareadon to one of the fires, where it collects a sample of fire sparks. They bring the sample to Alden, who’s impressed but also angry: She’ll have to face another tribunal for violating the rule against visiting human cities.

Sophie hears that Biana befriended her solely so her father could spy on her. Frustrated that no one seems to want her, she goes to a beach cave to be alone, but strangers overpower and kidnap her. Dex arrives at that moment, and the men kidnap him, too.

Her captors try to read her mind but fail. Someone rescues her and Dex, but he leaves them in Paris with a note that suggests they visit a bridge, where they find a lamp post that contains a crystal for light-leaping. The kidnappers reappear and try again to capture them. They wound Dex, but Sophie sends a powerful thought pulse that knocks them down. Carrying Dex, she light-leaps away, but without their protective nexus bracelets, the travel nearly kills them. Sophie reaches out mentally to Fitz, pleading for help. Fitz and Keefe find and rescue them.

Sophie takes weeks to recover. She broke several laws; the Council holds a hearing to decide her fate. They determine that, though she’s guilty, their own mistakes, plus the extreme pain she has suffered, mean that she has already been punished.

Finals are long over at Foxfire, but Sophie's Mentors vouch for her, saying that her recent, heroic use of the skills she practiced at school fully demonstrates her mastery of course materials. Her alchemy Mentor, though, simply can’t pass her—Sophie’s terrible at it—but Alden points out that she has manifested a new ability, inflicting pain with her thoughts, which qualifies her for a replacement class. Only Councillor Bronte is licensed to Mentor her in inflicting, and he promises to fail her. Still, Sophie can stay at Foxfire for at least another year.

The Council asks her to choose which family, Alden’s or Grady and Edaline’s, she wants to adopt her. Sophie chooses Grady and Edaline because together, they can heal from the losses they’ve suffered. Alden tells her it’s a wise decision. She thanks and hugs her friends for supporting her during a difficult time. Surrounded by them all, Sophie finally feels at home.