A forgotten hero returns - but will the truth behind his exile consume the world? Only the New Mutants can help young Loki now! Then, civil war breaks out among the British Manchester Gods! Even with Loki's aid, can Merlyn, King Arthur and Captain Britain prevail? And what does Hela want with the Holy Grail?! When the cursed Vanir return and declare war on Asgardia, Surtur's fire rages across the nine worlds! A desperate Loki journeys into the heart of Surtur's fiery kingdom, but the godling's future and past collide when Thor becomes trapped in the underworld - and the terrible truth about young Loki is finally revealed! Plus: Experience the ultimate mischievous team-up between Loki and Mister Sinister! Collecting JOURNEY INTO MYSTERY (2011) #637-645, EXILED #1, NEW MUTANTS (2009) #42-43, MIGHTY THOR (2011) #18-21 and material from A+X #5.