The story opens in the cosmic past, as Surtur the Fire Demon seizes on the molten core left by a supernova and begins to shape it with his tools, emitting an ominous "Doom!"
Then in a more down-to-Earth (literally) setting (Grant Park in Chicago, to be precise), Dr. Donald Blake basks in the sunshine while brooding over the burden of being Thor, God of Thunder. Suddenly, Don is hit by a Frisbee. No harm done—except a pair of powerful men hustle him into a car, where he is met by Nick Fury. The SHIELD Director reveals that he knows about Don’s dual identity—and wants Thor for a special mission. The car flies up to the Helicarrier where Thor sits in on a briefing. Jasper Sitwell relates how SHIELD’s telemetry unit picked up signs of an alien craft light-years away—a craft which absorbed the entire energy of a star to power itself—and the ship is now on its way to out solar system. Fury asks Thor to meet the ship and learn its masters’ intentions….
In Asgard, the lovely Lady Sif is unhappy that her beloved Thor has chosen to abandon her for Midgard (last issue). She seeks comfort from Balder but finds the brave warrior drowning himself in ale to forget his visit to Hela’s dark domain (issues #301-302). Sif then seeks out her brother Heimdall, the Guardian of the Rainbow Bridge and he tells her only Odin can help her….
The time-and-space spanning powers of his hammer allow Thor to intercept the vessel which appears to be a warship; simultaneously, the ship’s sensors detect Thor and identify him as a demon and a threat. The ship opens fire on him with energy bolts and the Thunder God responds by destroying the guns, then tearing an entryway into the craft’s side. The ship appears to be alive, automatically sealing the breach behind him. Exploring, Thor comes upon what seems to be a massive crystal coffin; as he leans over for a closer look, the inhabitant awakens from stasis and a four-fingered hand crashes through and grabs him by the face…..
Back in Asgard, a bored Loki hears a noise outside his window and looks out upon a forbidden troll hunt. As the warriors pursue their quarry with weapons at the ready, it is the beautiful Lorelei who captures the troll by tricking it into thinking her a kindly rescuer. Loki hatches a scheme and entices Lorelei into coming with him, while warning the warriors that Odin will not be pleased to learn of their illegally sport….
Aboard the alien craft, Thor is shocked to be so casually tossed aside by a huge and fearsome warrior who calls himself Beta Ray Bill. Bill takes Thor for a demon, one of his great enemies and launches a fight to the death; the ship Skuttlebutt, needing a landing site to repair its damage, heads for the nearest viable world—Earth. In the course of the melee, Thor is separated from his hammer and, being so near Earth, reverts to his alternate form of Don Blake. Beta Ray Bill easily knocks him out just moments before Skuttlebutt crash-lands in a remote area. The ship is quickly surrounded by SHIELD forces led by Nick Fury, demanding the alien’s surrender. Bill, believing himself surrounded by a horde of demons, searches for the intruder’s mighty weapon to fend them off—but finds only a thin stick of wood. In rage and frustration, he slams the stick against a wall—and is immediately transformed into the God of Thunder! Reveling in the might of the hammer, he staves off his foes—until the voice of Odin summons his son to Asgard, and Beta Ray Bill vanishes. Don Blake crawls from the wrecked ship and, realizing what has happened, cries out plaintively to his Father who has abandoned him to Earth….