The Sphere by Michael Crichton The Plot I find it hard to condense a plot of 370 pages to just a few pages; however, I will try my best.
It all started deep in the ocean, a group of scientists, each one specializes in a particular subject, are sent down to the bottom of the ocean to investigate a strange finding. The project is classified - Top Secret - no information is allowed to flow in or out. It turned out that the US navy had run into a strange craft of some sort. The navy believed that it is an alien space craft, because the technology used to construct the craft is yet unknown to humans.
The group, as it turned out, is a part of a project that Norman (the psychologist in the group) had been assigned to years before, by the army in case of first contact with alien beings.
So they went out to fulfill their mission with great uncertainties.
Our heroes went in the craft, and to their amazement they find English writings that suggested that the ship isn't an alien one. They finally figured out that the ship is probably from the future and that due to a malfunction something happened to it and it had got back to our time and era. In the ship they find futuristic contraptions and among all the common human-made devices they saw, they find a strange sphere which with no doubt is alien-made. They theorized what is it and what is its purpose and how to open it. The mathematician succeeded in opening it. He went in and the sphere closed behind him. They later find him lying on the floor disoriented and confused, but still they do not know how to open it or what exactly...