The Universe Between

THE DAY the phosphorescent cube materialized in his laboratory twenty years before, Dr. John McEvoy did not realize he had thrown open a door into an alien universe, parallel and contiguous with our own but organized in four linear dimensions instead of three.

Impossible to comprehend or even to investigate, that strange "Universe Between" had been labeled DANGEROUS TO EXPLORE! and McEvoy's project was hastily closed down.

But in the year 2017 the project has to be reopened. Seventeen-year-old Robert Benedict and his friend, young Dr. Hank Merry, are suddenly forced to make contact — somehow — with the Thresholders, the alien creatures who inhabit the Universe Between. With Earth desperate for natural resources, Dr. Merry's newly built transmatter seems the perfect way to transport iron, uranium and oil from other planets . . . until Robert discovers that the device is actually wrenching material through the other universe, driving the Thresholders to fight for their lives.

Robert has grown up in his own universe and in the Universe Between as well. Now, facing terrible danger, he ventures again and again into that alien world. Aided by Sharnan, a girl from the Threshold universe, Robert gropes for communication so that transport for the needed raw materials can be arranged and the violently dangerous transmatter be destroyed.

The solution Robert finds, and the electrifying truth he discovers about the real nature of the Universe Between, provide a breathless climax.

Dr. Nourse's startling book, intended primarily as a fast-moving, thought- provoking science fiction adventure story, illustrates at the same time some of the concepts and paradoxes of linear and temporal dimension in terms that are easy to understand. It explores the exciting idea of parallel universes — a notion that has fascinated scientists for centuries. Finally, it grapples with some of the problems that can arise in achieving understanding between alien cultures.

Portions of this book were originally published, in different form, in Astounding Science Fiction in stories entitled "High Threshold" (1951) and "The Universe Between" (1951).

Jacket by Mel Hunter