Sphere is a 1987 novel by Michael Crichton, his sixth novel under his own name and his sixteenth overall. It was adapted into the film Sphere in 1998. The story follows Norman Johnson, a psychologist engaged by the United States Navy, who joins a team of scientists assembled to examine a spacecraft of unknown origin discovered on the bottom of the Pacific Ocean. The novel begins as a science fiction story but quickly transforms into a psychological thriller, developing into an exploration of the nature of the human imagination. Plot summary A group of scientists (namely psychologist Norman Johnson, mathematician Harry Adams, zoologist Beth Halpern, astrophysicist Ted Fielding, and marine biologist Arthur Levine), along with U.S. Navy personnel, travel to a deep sea habitat at the bottom of the Pacific Ocean, where an enormous spacecraft has been discovered. During the descent, Levine becomes claustrophobic and is returned to the surface. The other scientists arrive safely at Habitat DH-8. After their arrival and subsequent pressurization to the habitat's exotic-gas environment, the Navy sends a robot to enter the spacecraft first, which locates and opens a panel near the spacecraft door. As the robot's cameras focus on the opened panel, labels in English indicate the spacecraft is actually a U.S. spacecraft constructed in the future and sent through time, appearing on the seabed at least 350 years before its creation. The robot is unable to open a hatch leading further inside, forcing the team to don pressure suits and explore the spacecraft. In a large cargo hold, the team discovers a mysterious spherical object that is clearly of extra-terrestrial origin. Reasoning the ship's future builders were apparently unaware that it had already been found in their past, Adams becomes convinced that the team will not survive to report their discovery. Remaining behind after the rest of the team returns to the habitat, Adams succeeds in opening and entering the sphere. Meanwhile, on the surface, a Pacific cyclone forces the supporting Naval ships to evacuate, trapping and isolating the scientists on the ocean floor for five days. Adams is found and returned to the DH-8 Habitat where he awakens with a terrible headache and little-to-no memory of how he opened the sphere or what occurred while he was inside. Immediately afterwards, the team is contacted by an intelligent, seemingly friendly alien entity that calls itself "Jerry". At first, Jerry communicates with the scientists