An exploratory push past the point of absolute zero opens a door to a bizarre, parallel universe. Seventeen-year-old Gail Talbot is the last to enter it and the only one to return intact. She turns thumbs down on the frantic men of science and keeps the secret of what she saw there, realizing that no adult mind, even her own, could cope with it. But eventually she passes her knowledge on to her son, who some twenty years later must act as liaison between the two worlds when science once mere tears the fabric between them. The result of this new breakthrough is catastrophic until Robert manages to communicate with the ""Threshholders"" and an agreement is reached. The ""Universe Between"" becomes a channel for matter transference and man gains the stars as well as new resources for a depleted earth. But there are some startling problems and some even more astonishing discoveries in store. Highly imaginative; posits some challenging concepts to the young scientist.