Underland Chronicles Books in Order

The Underland Chronicles begin in a very ordinary New York City apartment building. Eleven year old Gregor is doing laundry and watching his toddler sister Boots when she slips through a grate in the basement. Chasing after her, he falls miles beneath the city into the Underland, a vast underground world of violet eyed humans and giant talking creatures.

In Gregor the Overlander Gregor discovers Regalia, a hidden human city that rides bats into battle and lives in uneasy truces with rats, cockroaches, spiders, and more. A prophecy claims he is a long awaited warrior. Gregor insists that he only wants to find his missing father and get his sister home, but the quest to rescue his dad pulls him straight into a looming war.

Each of the five books sends Gregor back below for a new mission. In Gregor and the Prophecy of Bane he sails an underground sea to confront a mysterious white rat whose survival or death could shift power among the species. Gregor and the Curse of the Warmbloods follows a deadly plague that infects bats, humans, and other warm blooded creatures and raises unsettling questions about what lengths leaders will go to in the name of security.

Gregor and the Marks of Secret turns toward the mice, called nibblers, who begin to disappear in large numbers. Their trail leads to the Firelands, a volcanic wasteland, and to the realization that genocide is underway. The final volume, Gregor and the Code of Claw, brings open war between humans and rats, a seemingly fatal prophecy about Gregor himself, and a desperate attempt to end the cycle of violence.

Throughout the series Gregor grows from a worried, overburdened kid into a seasoned fighter who still clings to empathy. Boots provides comic relief and small flashes of courage, while allies like Princess Luxa, the rat Ripred, and the bat Ares show how fragile trust can be between former enemies. The prophecies that drive the plots are deliberately slippery, and much of the tension comes from how characters choose to interpret them.

Although the books are written for middle grade readers, they do not shy away from war, loss, or ethical gray areas. The tone balances big battles and creepy creatures with family warmth, wordplay, and the Underland's odd beauty. Readers who are not yet ready for the brutality of The Hunger Games often find Gregor's world a good bridge into Suzanne Collins's larger themes.