Young Mollie traverses eerie, perilous lands to retrieve her baby brother, Thomas, from the Kinde Folke, malicious sprites who snatched him and left a hideous changeling in his place. When her adorable baby brother is replaced by an ugly, ill-tempered changeling, Mollie is determined to find the so-called Kinde Folke who took baby Thomas, return the changeling she calls Guest, and make them give Thomas back.

Winston Chu saves the owner of a curiosities shop from a robbery only to be gifted a broomstick and a dustpan for his trouble--items that turn out to be more a curse than a blessing when they sweep away important stuff, like his baby sister.

"An autistic changeling trying to navigate her unpredictable magic, Seelie finds it difficult to fit in with the humans around her, unlike her twin sister, until they both get caught up in a heist gone wrong that changes everything." -- Provided by publisher.

When Wendy Everly was six years old her mother was convinced she was a monster and tried to kill her, and eleven years later Wendy learns that her mother was right and that she is actually a changeling troll, who, at the age of seventeen, must be returned to her rightful home.

"We rejoin our heroine for her latest adventure just as she awakes to find herself ... in the body of a troll! Her mother is worried sick, and is perplexed by the strange creature that seems to have taken Hilda's place. Now, both of them are in a race to be reunited before Ahlberg and his safety patrol get the chance to use their new secret weapon to lay waste to the trolls, and Hilda along with them!"--Provided by publisher.

Tracker Bryn Aven's goal of becoming a member of the elite King's Guard is threatened when she is sent to stop Konstantin, a fallen hero who she once secretly loved, who appears to be kidnapping changelings.

Pikey Thomas doesn't know how or why he can see the changeling girl. But there she is. Not in the cold, muddy London neighborhood where Pikey lives. Instead, she's walking through the trees and snow of the enchanted Old Country or, later, racing through an opulent hall. She's pale and small, and she has branches growing out of her head. Her name is Henrietta Kettle. Pikey's vision, it turns out, is worth something. Worth something to Hettie's brother...

"A young troll named Hawthorn is stolen from Fairyland by the Golden Wind, and becomes a changeling in our world, a place no less bizarre than Fairyland in his eyes." --

Sixteen-year-old Mackie Doyle knows that he replaced a human child when he was just an infant, and when a friend's sister disappears he goes against his family's and town's deliberate denial of the problem to confront the beings that dwell under the town, tampering with human lives.

"At age twelve, grave robber Thomas Marsden discovers a boy who looks just like him in an unmarked grave and begins a journey of discovery as he learns of faeries trapped in London and their hope that he can return them to their realm." Provided by publisher.