Dr. John Hanson, is a renowned physicist who during an experiment is inadvertently transported into a parallel universe that he later finds has evolved in a totally different way due to the omission of one important historical event. As he becomes more familiar with the world he is now part of, he realizes to his horror that his own universe, the world he has left behind, will soon be threatened by this parallel universe he has found himself in. He has to try and prevent the two worlds' colliding, even if he has to pay the ultimate price.