It is revealed in "The Restaurant at the End of the Universe" that Jeltz had been hired by Gag Halfrunt to destroy the Earth (though in the film it was Zaphod who gave the order by mistake). Halfrunt had been acting on behalf of a consortium of psychiatrists and the Imperial Galactic Government in order to prevent the discovery of the Ultimate Question. When Halfrunt learns that Arthur Dent escaped the planet's destruction, Jeltz is dispatched to track him down and destroy him. Jeltz is unable to complete this task, due to the intervention of Zaphod Beeblebrox the Fourth, Zaphod's great-grandfather.