Advanced beings from a parallel Earth have developed the ability to travel between universes. Unfortunately their innate xenophobia prevents them from exploring the multiverse. Solution: contact two scientists from two different universes to explore for them and record their experiences.
Jonnan Mayne is a high-ranking scientist on his Earth, and Ithleen Danir is from an Earth whose surviving population live inside a domed city. When they practice making transfers using the alien technology they catch the attention of Haughn, a dictator of a militaristic Earth, who sets out to steal the technology. Haughn's attempts put Mayne, Ithleen and a few accidentally acquired companions in danger.
Now the struggle to survive is fought across the Multiverse in this adventure reminiscent of the Golden Age of science fiction.