In 1573 Edward is digging graves for Black Death victims when he unknowingly enters an unstable wormhole created by scientists in London in the year 2050. But in Edward's world the queen in 1573 is Jane and not Elizabeth. One scientist, Laura Rebas, understands that Edward has not travelled in time from the past, but has travelled from a parallel universe in which the present is similar to but not identical to our past. Zebra, who monitors wormhole creation from a universe in which people have learned to perceive and move about in four spatial dimensions, has observed Edward's travel between parallel universes. He tells Edward that the creators of the wormhole do not understand the dangers that it poses and that the wormhole that he traveled through must be destroyed.