Character(s):
Superman (origin retold); Halk Kar (intro); Jor-El (flashback); Lara (flashback); Wrecker Ross (intro, villain); Lois Lane
Synopsis:
When Halk Kar crashes on Earth, the note he carries in Jor-El's handwriting makes Superman suspect that Halk Kar is his older brother. But when Halk Kar joins Superman in his pursuit of "Wrecker" Ross, Halk Kar receives an electric shock and remembers that he is actually a space traveller from Thoron who met Jor-El on Krypton just before it exploded.
Notes:
Many elements from this story re-used in "Superboy's Big Brother" in Superboy (DC, 1949 series) #89, making Halk Kar retroactively "Earth-2's Mon-El."