"A genre-bending, heart-pounding middle-grade romp into a potential future. . . . Perry's layered approach makes for a masterpiece that feels both familiar yet wholly new." --Shelf Awareness, STARRED REVIEW

"This takes getting lost in a book to a whole new level. I loved it!" --James Riley, New York Times-bestselling author of the Story Thieves series

"Once you start this book, you truly can't stop. An adventure full of cheeky charm and delightful whimsy." --Marie Lu, #1 New York Times-bestselling author of Skyhunter

"A fast, fun, furiously inventive, and frequently frightful read." --Geoff Rodkey, New York Times-bestselling author of the Tapper Twins series and We're Not from Here

This clever, fast-paced adventure is a mix of the Story Thieves series and Ready Player One!

Oliver Nelson has a terrible secret-he's a thief.

But he only steals books from the Garden Grove Library that are old, musty, brittle, or incomplete, like his favorite book, The Timekeeper's Children. No one reads anymore, and surely no one will miss them, right? Wrong.

The Pribbles are famous inventors of the most popular toy in the world, alternate-reality goggles. They are also book collectors who are searching for The Timekeeper's Children, so the Pribbles hatch a plan. They invite Oliver, the last person to have checked it out, to their mansion and use special software from their goggles to steal the last remaining copy of the book--from inside Oliver's mind.

Now, Oliver is thrust into the middle of the story and must help the main characters steal pieces scattered around the fictional world of Dulum to build a magical clock that can turn back time before the evil sorcerer Sigil takes over. They'll encounter hideous giants, bloodsucking bats, vicious eels, a Nasty Rodent Eater, a gang of wicked children, and a strange, dark figure that follows them from chapter to chapter, all the while with the Pribbles in pursuit.

Can Oliver save Dulum before Sigil destroys everything? And will he finish The Timekeeper's Children before the Pribbles steal it from his mind?