Doomsday theory explores how the Fantastic Four might travel to Earth-616. It suggests Reed Richards uses Galactus’ ancient ship tech, combined with his own inventions, to build multiversal transport and rescue Franklin Richards from Doctor Doom’s grasp.

Doomsday connects to The Fantastic Four: First Steps? A key mid-credits scene introduces a mysterious presence, hints at a growing multiversal threat, and sets up one character’s deeper interest in Franklin Richards.