When Lorraine Lewis was kidnapped by the forces of the Underworld Kingdom, Brad Hardy descended into the caverns to rescue her, discovering a vast subterranean world of forests, mountains, and underwater cities, inhabited by Snake Men, Rat Men, Bat Men, Ape Men, Dre, and Grey People. Early on in his rescue mission he encountered and befriended a magician, Prince Kardos of Agharti.
- This version of Brad Hardy, including all history and corresponding appearances, was erased from existence following the collapse of the original Multiverse in the 1985–86 Crisis on Infinite Earths limited series. Even though versions of the character may have since appeared, this information does not apply to those versions.
- The 28-episode career of Brad Hardy was marked by several changes from one writer/artist to another, starting at New Fun Comics #3 with Richard Loederer, changing at New Fun Comics #6 to W.C. Brigham, then again at More Fun Comics #9 to A. Leslie Ross, and again at More Fun Comics #12 to Tom Hickey, who stayed with the feature until its final episode, in More Fun Comics #31.
- 29 Appearances of Brad Hardy (Earth-Two)
- 1 Images featuring Brad Hardy (Earth-Two)
- Quotations by or about Brad Hardy (Earth-Two)
- Character Gallery: Brad Hardy (Earth-Two)