It was just before Summertide, the time when the twin planets, Opal and Quake, would orbit closest to their sun, subjecting both—but Quake in particular—to vast tidal forces. And it was to be the most violent Summertide ever, due to the Grand Conjunction of the system's stars and planets, something that happened only every 350,000 years. Access to the unstable Quake was supposed to be prohibited, but some very insistent travelers were determined to make the trip. Professor Darya Lang, who had made a career studying artifacts left by the long-vanished aliens called the Builders, had a hunch that during this unusual Summertide she might find the Builders themselves. Louis Nenda and the Cecropian Atvar H'sial had their own interests in Quake, and would do anything to get there. And Councilor Julius Graves was hunting murderers—if they were hiding on Quake, he needed no one's permission to search for them. Planetary Administrators Hans Rebka and Max Perry had no choice but to go to Quake themselves—risking their lives to protect the others—and to learn, just maybe, the secret of Summertide and the Builders...

Following the planetary upheaval known as Summertide, the inhabitants of Quake come closer than ever to discovering who the Builders, the creators of incredible constructs, had been

Set loose after millions of years trapped in stasis, a handful of Zardalu are transported to galactic parts unknown, free to ravage any world and any race within their grasp. Reprint.

The discovery of an ancient alien technology known as the Artifacts enables the human race to jump from galaxy to galaxy, but when a strange new Artifact emerges and changes all the other Artifacts, chaos ensues.

Hans Rebka, interstellar trouble-shooter, had solved the mystery of the gigantic Artefacts and defeated the warlike Zardala - but that was only the warm-up for the main event. In one arm of the galaxy, something is destroying whole stellar systems, Rebka and his motley crew discover a battle beginning.