Sif and Thor are separated when his father Odin banishes Thor from Asgard and Thor begins a life as a superhero on Earth. Many years later Thor becomes romantically involved with Jane Foster. Thor brings Jane to Asgard to be wed and she is granted immortality but fails a final test. Odin sends her back to Earth, stripped of her newly acquired powers and without memories of the event. Odin then arranges an encounter with Sif while Thor is battling the monstrous super-strong Unknown and the two fall in love again.