Keeper of the Lost Cities

Morrigan Crow expects her cursed birthday to be her last, until she is taken to the secret city of Nevermoor and asked to compete for a place in a remarkable society. Nevermoor shares Sophie's sudden discovery that the ordinary world has hidden rules, unusual talents, and friendships waiting beyond it. Jessica Townsend's story has a more whimsical city and a single structured trial at its center. Choose it if Foxfire's school life and Sophie's search for belonging were the appeal, but you want a fresh setting and an underdog heroine with a different kind of mystery.

Amari receives an invitation to a secret summer program after her brother disappears, then learns that supernatural abilities exist behind the familiar world. Amari and the Night Brothers has the hidden institution, gifted young heroine, rivalries, and larger conspiracy that Keeper readers often enjoy. B. B. Alston sets the story against Amari's experience of being underestimated because of race and class, giving its belonging question a different edge. Its summer-camp structure also moves faster than Messenger's sprawling series. Start here for another girl who refuses to accept the adults' account of her family.

Kendra and Seth spend a visit with their grandparents discovering that the property shelters magical creatures under strict rules. Fablehaven shares Keeper's wonder at a secret society existing beside everyday life, along with danger when young people learn why those rules matter. Brandon Mull gives the sibling pair a preserve to explore rather than a school to attend, and the creatures draw from a broader folklore mix. Choose it if the appeal was discovering how a hidden magical world works, and you are happy to trade Sophie's friendship circle for family teamwork.

Percy Jackson learns that he is a demigod and is sent to a camp where new friendships and dangerous quests follow quickly. The Lightning Thief shares Sophie's shock at discovering a concealed identity and a world of powers adults have hidden from her. Rick Riordan keeps the voice funnier and the action more episodic, drawing on Greek myth instead of Messenger's elven society. This is a natural next read when the secret-school and found-friendship pieces mattered most, though Percy's quest structure leaves less room for the same slow-burn mystery.

Sophie and Agatha are taken to a school that trains fairy-tale heroes and villains, only to be placed where neither expects. The School for Good and Evil shares Keeper's school friendships, class rivalries, and suspicion that the institution knows more than it admits. Soman Chainani is more satirical about labels of good, evil, beauty, and friendship. It has a darker fairy-tale bite and a tighter focus on the girls' changing bond. Choose it if Foxfire's social world was fun but you want its rules challenged more directly.