Synopsis
This is a story set in Thor's past, and doesn't involve any others of the Uncanny Avengers. But Kang brings his sub-plot from last issue to the foreground.
In 1013 Thor is visiting some Vikings for drinking and brawling. Basically what Hercules has tended to do. He carries the axe Jarnbjorn.
Suddenly his fun is interrupted by Apocalypse, who bests him in physical battle after his armour proves immune to a blow from Jarnbjorn. Thor leaves in his goat-drawn chariot (declaring it not a retreat but a tactical breather).
Apocalypse's flying pyramid has been hovering in the background, which the villain now enters to meet with his ally Pharaoh Rama-Tut. Tut expects Apocalypse to have killed Thor, but Apocalypse says he wasn't worth the effort. Tut insists that Thor will be a major thorn in both their sides in the future.
Apocalypse then demands Rama-Tut tell him the name of a man whose descendant Tut swore would be Apocalypse's bane. Tut pretends to be bullied into it, and speaks of Folkbern Logan in London.
Thor goes to father Odin and demands to know how to get through Apocalypse's armour. Odin warns him off because Apocalypse works for the Celestials, and Odin has a pact with them.
Kang disguised as Loki fetches a spell from Odin's library that will render Thor's axe capable of hurting Apocalypse. The spell was kept in case the Celestial Executioner comes to destroy Earth. Only Odin or a blood-relative like Thor can cast it.
Folkbern is a guard on one of London's bridges. The Four Horsemen of Apocalypse attack, incinerating his fellow guard. Folkbern prays to his pagan gods, and is astonished to get an answer in the form of Thor, who quickly despatches the 4 foes with enchanted Jarnbjorn.
Apocalypse in his pyramid isn't happy. But Rama-Tut chooses this moment to disappear back into the timestream. The angry mutant attacks London directly with his pyramid's weapons. Thor tries to kill him with Jarnbjorn, but Apocalypse plucks the axe out of the air and hurls it back to bury itself in Thor's chest.
Then he foolishly turns his back on his downed foe. Because Thor rises up and slices through Apocalypse's shoulder to the heart, armour and all. The dying mutant triggers a self-destruct in his pyramid, and Thor only just makes it out in his flying goat-chariot.
Back in Asgard Thor is celebrating his victory when Odin storms in. The angry All-Father claims that the enchanted axe will be a grave danger to future Asgard and Midgard. And it will be Thor's job to keep it safe.
Skip forward to the present day in the tomb of Baron Mordo in Brazil. The cause of death is readily apparent as Mordo has Jarnbjorn embedded in his skull. Kang arrives to claim the axe. It appears Mordo tried to take the axe from Thor, but only gained it in death. (For some unexplained reason Thor couldn't take it back, but this doesn't seem to hamper Kang.)
Kang removes his helmet, revealing the face of Rama-Tut. He cryptically mutters "The 7 nust be 1. The termites eat upon my foundation". But it seems this whole issue has been his scheme to get a weapon capable of harming Apocalypse (or maybe Celestials).