Ring is a science fiction novel by Stephen Baxter. A weathly cult, Superet, funds a probe to investigate the sun, hopefully to discover why the number of neutrinos it is releasing is so low. Lieserl, a human, is engineered to provide a conscious in-situ control of the probe. She discovers the reason for the lack of neutrinos, and it's a plague that is destroying all the stars.

An expedition is mounted to use relativistic travel to pass 5,000,000 years into the future to investigate. They return to find the remnants of vast engineering projects, and the signs that humans fought and lost a war against the Xeelee, the rulers of the universe. Talking with Leiserl who has observed the events of the past 5,000,000 years, leads them to investigate the Great Attractor, rumuored to be the greatest engineering project of the Xeelee; the lords of the universe. The Xeelee's project offers them the only hope as the stars fade and die.....

Again Stephen Baxter puts the science into science fiction, and proves he can think further and deeper than most. A book of vast scope and vision, and one that can be re-read many times!