While responding to an emergency call, Thor, in his mortal guise of Jake Olsen, found himself under attack by what he assumed was Gladiator. The attack killed his fellow paramedics and gave the impression to those around the wreck that his mortal identity was also dead. Thor survived the attack and after a brief battle found that the Shi’ar Gladiator was actually a Skrull. Before killing himself in an explosion, the Skrull told of a further plot a distance away within a mountain.

With great haste Thor traveled to the site of this hidden plot, but before he could breach the doors was attacked by an old friend, a battle brother and wielder of the weapon from which he drew his name, the Thunderstrike. This warrior’s real name was Eric Masters and, though brothers in arms, Thor fought him and within the facility bested him. Inside he found another Skrull and two other bodies in mid-transformation. He also discovered that Eric was not a Skrull but instead of an unwitting pawn to the schemes of the aliens. Dissolving away he left Thor with only questions and the now-shattered Thunderstrike.

Meanwhile in the lands of Jotunheim Loki (disguised as Thor) attacked first a Troll village, slaughtering the lot of them, and second the King of the Giants Utgard Loki's son Prince Olregrim. He killed Prince Olregrim and left his body as a message to the Giant King. In this way he sent the Giants and Trolls against the Asgardians in war. Thor meanwhile appeared in Asgard, seeking answers and speaking with his father. He was told to wait as a great victory had been done by his longtime allies the Warriors Three who had slain a great dragon. At the feast set for this victory, the Asgardians were attacked by the army of the Trolls and Giants. This attack was facilitated by the God of Mischief Loki who during the feast had defeated and greatly injured Heimdall to keep him from warning the All-Father.

Using fell magicks, the Trolls removed Odin and a number of other gods from the battlefield and a pitched battle began. During the attack, Sif was badly injured when the mightiest of the Trolls, Ulik, began his attack. Driven to a warrior’s madness, Thor took the fight to the mighty Troll and during the struggle (unbeknownst to either warrior) they freed from a hidden room the God of Might, Magni, son of Thor. Magni's timely intervention saved Thor and defeated Ulik after a titanic battle.

Odin, awakened by Idunn, quickly drove the invading army out of Asgard and the injured were taken care of, including Sif, Thor, and Magni himself. While the attack was happening, Loki used it as a diversion to break into the palace and, upon finding the well of Mimir hidden in the great library, finally obtained the information he sought after that would lead him to power enough to conquer Asgard.

After the battle for Asgard was over, Odin called forth the recovering Magni Thorson and talked with him about his memories and his origin and discovered that Magni was from a past cycle of the life of the Asgardians. Magni's only memories, which to him were seemingly hours earlier, were of Ragnarok and Loki's foul treachery which he had taken the attacking forces to be part of. Though Odin welcomed the young god as his own grandson, he advised that Magni keep his origins to himself, even from Thor. With Magni dealt with, Odin returned to the library and, with the Odinforce, discovered what Loki had done while Asgard was invaded. To his horror, Loki sought what he had hidden years before and now, with the treacherous Mimir's aid, had found it within Hel. With war upon them, Odin turned to Thor, his trueborn son, to find and stop his traitorous kin. Leaving Sif's protection in the hands of the warrior who saved him, Magni, he stepped into a portal to Hel.

Upon arriving, Thor was confronted by the Captain of the Valkyrior Axe who had been tasked with protecting Hel's gate. Before the matter of entry was resolved, both were attacked by Thor's allies in the Avengers who were under the control of Lorelei, the sister of the Enchantress. Though the battle was mighty, Thor was able to stave off the attack and, with the aid of the Lady Liberators, win the battle and free his friends. He bade them farewell as the quest he was on was of a personal matter best settled by Asgardians alone. It was then that the pair found the gates to be an illusion and that Loki had entered Hel. With all haste, the pair of warriors entered Hela's domain.

To be continued in The Mighty Thor #8!