The Reefs of Time: Part One of the "Out of Time" Sequence (Chaos Chronicles, Band 5)

The starstream is beautiful. But beauty turns deadly when an ancient AI bent on destruction uses it to travel uptime, to humanity's future.
The Mindaru are dead. Or so exiled-Earthman John Bandicut and his alien companions believe, after their intervention to save the Orion Nebula and surrounding worlds. But now a part of this ancient and malicious AI colony is swarming toward the present from its birthplace deep in the past. Their opening: a temporal disturbance in the starstream, a hyperspatial thoroughfare used by myriad civilizations. The disturbance emanates from the planetary defenses of nearby Karellia, whose people know nothing of the starstream or the galaxy-threatening Mindaru.
Only Bandicut and his friends have the knowledge and experience to act. But when several of the company go missing, he and Li-Jared must team with the pandimensional Ruall and her gokat-the oddest aliens Bandicut has met since the shadow-people-and journey to Karellia to find a way to cut off the timestream.
Meanwhile, on Shipworld, the "missing" Ik meets another human of Earth-a former lover of Bandicut's-and embarks with her on a perilous mission far back into deep time, seeking a way to stop the Mindaru at their source.
The Chaos Chronicles returns at last with part one of a heartstopping, two-part adventure. Concluded in Crucible of Time-coming soon from Nebula-nominated Jeffrey A. Carver!