The Earth seems to stop spinning and behind this strange phenomenon the shadow of Zorglub soon appears. But Zorglub behaves strangely, delegating contradictory orders to his robot Zero who no longer understands anything. Spirou and Fantasio lead the investigation, surprised by the mad scientist's unusual demands.
Zantafio develops a hypnosis process on the sweet Luna (the daughter of the mafioso Vito Cortizone) in order to make her commit repeated thefts of different components aimed at becoming, once assembled, the most powerful weapon in the world.
Zantafio is a cousin that Fantasio had lost touch with, but he joins forces on an expedition that brings together our two heroes and Champignac. The goal of the expedition is to find the “Hammer of Thor,” a Viking antiquity with supposed powers, lost in the ice.