As Thor and the Warriors Three set out on the search for Sporr, the monster which has carried off Sif, Relstor, leader of the world-ship Levianon, relates the history of his people. Their world was a peaceful paradise until an ecological disaster doomed it. Before its final destruction, refugees set out in the massive ship in search of a new home. Sadly, the people were far too used to their decadent lifestyle and the ship fell into disrepair. Then a meteor hit introduced the alien Sporr into their system where it now preys on the weak and aged among them. The party encounters the monster again and again it barricades the corridor against pursuit….
In Asgard, Balder surveys the enemy forces encamped outside the gates and questions his ability to lead; Karnilla is annoyed once more….
Thor clears the blocked passage with his mighty strength, and the search party continues They come face-to-face (sort of) with Sporr, a huge blob with a single eye. The Thunder God and his warriors attack and after a great struggle ending with Thor calling down lightning on their enemy, they kill it. Thor tears down the door the monster was guarding to find…all of the missing people unharmed. Sif explains that Sporr was a kindly alien who wanted to create a leisurely paradise for the infirm among the Levians—and their fear caused them to turn it into hell.
Epilogue: a warship zooms through space; it is a pirate ship commanded by none other than Thor’s old foe, the Grey Gargoyle….