The World at the End of Time — Frederik Pohl

The Denver Post

Wan-To was the oldest and must powerful intelligence in the universe, a being who played with star systems as a child plays with marbles. Matter occupied so tiny a part of his vast awareness that humans were utterly beneath his notice.

The colonists of Newmanhome first suffered the effects of Wan-To's games when their planet's stars began to shift, the climate began to cool down, and the colony was forced into a desperate struggle to survive.

Viktor Sorricaine was determined to discover what force had suddenly sent his world hurtling toward the ends of the universe. And the answer was something beyond the scope of his imagination -- even if he lived for 4000 years...