The eccentric scientist Frieda Hofstätter is on the verge of being cast aside. Then the Valkyrie Wolkentruth appears to take her to Valhalla. But Frieda refuses and strikes a deal: Wolkentruth must help her save Frieda’s CO2-storing miracle mushroom. Only then may she take Frieda with her. Together, they race against time—and perhaps for the future of the world.