Join Thor and his family on a titanic tour of the Ten Realms! Witness the ancient origin of Yggdrasil the World-Tree! Thor leads a desperate battle against the relentless Mangog — for Asgard! Learn how a foolhardy adventure in Niffleheim led young Thor to be banished! Loki declares war on Midgard — and visits his childhood self in Jotunheim! From Svartalfheim, Dark Elf Malekith plots to unleash the Casket of Ancient Winters — and Odin recalls the ancient trip to Muspelheim that began his age-old rivalry with Surtur! Plus: Alfheim! Vanaheim! Nidavellir’s role in the origin of Mjolnir! And the stunning revelation of the Tenth Realm of Heven!