The Icarus Twin by Timothy Zahn

A NEW NOVEL IN THE ICARUS SERIES FROM NEW YORK TIMES BEST-SELLING AUTHOR OF THE ADMIRAL THRAWN STAR WARS NOVELS TIMOTHY ZAHN
For years Gregory Roarke and his Kadolian partner Selene worked as crocketts, combing through the atmospheres of uninhabited worlds for places that might be colonized or hold valuable resources. Now, they quietly work for the Icarus Group, a top-secret government organization hunting for portals created by a long-vanished alien race, portals that can teleport a person hundreds or thousands of light-years in the blink of an eye.
Roarke and Selene are searching one such possibility when they find that someone appears to be stalking them. They evade their pursuers and return to find that a man named Easton Dent has been searching the Spiral's databases for the names Gregory Roarke and Icarus.
Roarke reluctantly agrees to meet with him. But that first contact is cut short, and hours later Roarke is arrested and accused of Dent's murder.
More importantly to Roarke's Icarus Group overseers, that brief meeting also confirms that Dent was in recent contact with a portal.
But the alien Patth are also searching for such portals, and they are also on the trail. It's now a race . . . and the Patth have resources and ruthlessness far beyond anything Roarke and Selene can match.
At the publisher's request, this title is sold without DRM (Digital Rights Management).