House of Mystery started out as a horror anthology, featuring tales of the supernatural as well as supernatural-themed mystery stories. However, with the growing backlash against horror comics in the mid-1950s, as well as the advent of the Comics Code Authority and its restrictions on horror-themed storylines (banning stories dealing with such supernatural fare as werewolves, vampires, and such), the series quietly was revamped into dealing with science-fiction type monsters and other mystery-suspense type tales that were permitted by the comic code.
