The Callistan Menace

In his autobiography, I, Asimov: A Memoir, the author recalled that Campbell sent him a rejection letter that was so kind and it prompted him to write another story called "Stowaway" ("The Callistan Menace").

Suspecting that Campbell would reject it, Asimov spent the subway ride home coming up with the plot for a third story, "Marooned off Vesta".

He accepted "Magnetic Death" on 16 November 1939, and it finally appeared in the April 1940 issue of Astonishing Stories under the title "The Callistan Menace".

Two crewmen discover a stowaway in the supply room, a 13-year-old boy named Stanley Fields who believes in the heroic spacemen and villainous pirates of dime novels.

The crew adopts Fields as a mascot, even repairing an obsolete rubber space suit for him, and the stowaway's presence distracts others from the death they fear is likely.

The captain of the Ceres realizes that the slugs are using magnetic fields to stun the crewmen, amplified by their steel space suits.