Tony Stark is in his laboratory at Avengers Tower, experimenting with an advanced device designed to detect dimensional anomalies. However, a malfunction unexpectedly tears open a portal to another universe, and a woman falls through it by accident, landing right in the middle of his laboratory. Neither of them knows how the incident happened, or that they are essentially counterparts from two different universes. To Tony's astonishment, she possesses the same extraordinary intelligence, inventiveness, confidence, sarcasm, and stubbornness as him—and she is the Iron Woman of her own universe.