In the hard-science Tomorrow & Tomorrow , Sheffield explores changes in the solar system and the theory of a closed vs. open system wrapped around a tale of a musician’s fanatical love for his wife. Drake Merlin has his dying wife Ana and himself cryonically frozen so they can be together once a cure for her disease is found. Several times over 15 billion years he is awakened only to find no cure and, one time, he accidentally causes Ana’s death. But if the theory of a closed system is true and the universe shrinks, he and Ana can return to a point when she is alive.

Banned from interstellar travel for their aggressiveness, humans have one last chance to regain the stars, provided they can solve the mystery of the disappearance of a pair of alien ships lost somewhere in the unknown part of space known as the Geyser Swirl. This sequel to The Mind Pool continues Sheffield’s far future history of humanity’s attempts to explore the universe. His skill at blending hard science with fast-paced plotting and colorful characters makes this a first-rate SF adventure that belongs in most libraries.

CALLING ALL HUMANS...In the 23rd century, out of all the races of the galaxy, only humanity has discovered the secret of travel between the stars -- not so much because we're so smart, but because we are incredibly gadget-oriented. We are also, compared to the galaxy's highly sophisticated norms, very, very tough, which most of the time does nothing for our social acceptability. But when a threat to all life in the galaxy arises from non-living biological constructs, suddenly the peculiar human virtues of valor and stubbornness make us the sword-wielding saviors of All....

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 unusal 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…

From Publishers WeeklySheffield, known for both rigorous hard science fiction ( Cold as Ice ) and pulpy space opera ( Transcendence ) combines the two in this space adventure with a background of speculative science and the plot and characters of a Flash Gordon serial. On the isolated planet of Erin, young Jay Hara has grown up on dreams of space and legends of the fabled Godspeed drive, which once allowed humans to travel at translight speeds. After meeting Paddy Enderton, a seedy old spacer, Jay is drawn into a chase which carries him off the planet, into the asteroid belt and its tiny worldlets, and finally to the remnants of an ancient space station where the Godspeed drive may still exist. Along the way, Jay is at once awed and terrified of the piratical spacers who crew the ship, particularly the smooth-talking, ruthless captain, Daniel Shaker. Struggling to reconcile his admiration for Shaker with the man's evident viciousness, Jay eventually comes into his own as a spacer and an adult. With this voyage of development, Sheffield raises his undemanding story above its otherwise rather hackneyed science fiction elements. Copyright 1993 Reed Business Information, Inc. From Library JournalTo the citizens of the planet Erin, the Godspeed Drive is a legendary device from a lost age before the isolation of the Forty Worlds. To teenager Jay Hara, however, it is his one chance to claim his future in deep space--if he can find it. The author of Cold as Ice ( LJ 6/15/92) sets this coming-of-age adventure against the backdrop of a planet struggling in quiet desperation to hold onto the remnants of a dying technology. Despite the high-action content of his plot, Sheffield never slights his characters or his science. A good choice for most sf collections.Copyright 1993 Reed Business Information, Inc.

The sky is falling — again. Following up on 1998’s excellent Aftermath , Starfire subjects planet Earth to yet another cosmic blast from the Alpha Centauri supernova. But while the blast that hit Earth in Aftermath simply cooked the Southern hemisphere and knocked out unshielded technology with a flash of gamma rays, this wave promises to do some real damage, with a sleet of trillion-nuclei bundles moving at one-tenth the speed of light. Warned by the first catastrophe, Earth began building an electromagnetic shield out of the orbiting SkyCity station to divert the incoming apocalypse. But not only will the storm come earlier than expected, the carnage may be worse than anyone imagined — preliminary data shows that the supernova was no accident, and that the wave of particles may in fact be a beam. Crackerjack hard-SF author Charles Sheffield brings back much of the cast of Aftermath for this suspenseful, well-paced follow-up, the two most satisfying returnees being sociopath-savant Oliver Guest and his former patient Seth Parsigian. In the book’s subplot, the brilliant Guest and gruff Parsigian must team up to solve a string of grisly child murders on Sky City that threatens to push the shield project even further behind schedule.

In the aftermath of the “summertide” that nearly destroyed twin planets of Opal and Quake, a few humans and aliens representing various civilized worlds confront the remnants of an ancient technology and discover a threat to life as they know it. Excitement builds rapidly in this fast-paced sequel to Summertide . Recommended for large libraries.

In the 22nd century biofeedback techniques have enabled humans the ultimate expression—the ability to transform the body into any viable form. What began as an innocent technique to reduce anxiety without drugs has raised fundamental questions about what it is to be human. Enter the Humanity Test.