Avatar: The Last Airbender - Smoke and Shadow, Part 2 (Smoke and Shadow, #2)

What is the secret of the Kemurikage?

The shadowy spirits known as the Kemurikage are abducting children throughout the Fire Nation Capital, sowing widespread fear and panic in their wake. Desperate to determine what has angered these spirits, Aang and Zuko search for clues deep in the Dragonbone Catacombs underneath the Fire Sages Capital Temple. Can they uncover the hidden history of the Kemurikage and solve the mystery in time, or will more children be taken?