The story is about a mysterious spacecraft found at the bottom of the Pacific. The Navy flies in a psychologist (Norman) and a team he has recommended (which includes a biologist, a physicist and a brilliant mathematician) to investigate it. They go down to the depths to live in a specially pressurized habitat. The spacecraft is indeed fabulous once they discover that is was built for space-time travel. Inside this craft they find a large sphere. They can't figure out what this sphere is meant for or its contents. They can't return to the surface too since a Pacific storm has now left them stranded with no surface support. As they race to find out the secret of the sphere, strange things start happening in the deep ocean around their habitat.

The Sphere is not a sci-fi novel, it is a psychological thriller. The mind games are real neat. There is lot of trivia bits about science which are interesting. The best is Ted's explanation of how gravity connects space and time together. He does it using a bowl of fruit! Sphere is a good read.