Thirteen year-old Gabriel Hunter survived Kata-Tartaroo and wants to go home, which is surprising for a Lesser like him, but instead he and his friends, Owen and Corinna, are forced into another terrifying world - Bibliotheca - where the sun never shines, the temperatures are freezing and the snow pummels you. To make matters worse, Gabriel and his friends have been taken captive by Yugs. The Yugs will send these three back home, but only if they agree to help with their mission: Enter the Building of Books, a magical labyrinth filled with dangerous puzzles, locate the Command Center, and outsmart the Wolf before he outwits them. In this fast-paced follow-up to Welcome to Kata-Tartaroo, Gabriel, Owen, and Corinna must rely on each other to save themselves and save the Yugs. Along the way, secrets will be revealed, friendships will be renewed, and Gabriel will learn leaders come in all shapes and sizes. It's a race against time to see if Gabriel and his friends will solve the puzzles and destroy the Wolf or be left in Bibliotheca forever.