Neanderthals have developed a radically different civilization on a parallel Earth. A Neanderthal physicist, Ponter Boddit, accidentally passes from his universe into a Canadian underground research facility. Fortunately, a team of human scientists, including expert paleo-anthropologist Mary Vaughan, promptly identifies and warmly receives Ponter. Solving the language problem and much else is a mini-computer, called a Companion, implanted in the brain of every Neanderthal. But it can't help his fellow scientist back in his world, Adikor Huld, when the authorities charge Adikor with his murder.

Experimental psychologist Jim Marchuk has developed a flawless technique for identifying the previously undetected psychopaths lurking everywhere in society. But while being cross-examined about his breakthrough in court, Jim is shocked to discover that he has lost his memories of six months of his life from 20 years previously - a dark time during which he himself committed heinous acts.

When prospector Bob Broadhead went out to Gateway on the Heechee spacecraft, he decided he would know which was the right mission to make him his fortune. Three missions later, now famous and permanently rich, Robinette Broadhead has to face what happened to him and what he is...in a journey into himself as perilous and even more horrifying than the nightmare trip through the interstellar void that he drove himself to take!

A scientific experiment begins, and as the button is pressed, the unexpected occurs: everyone in the world goes to sleep for a few moments while everyone's consciousness is catapulted more than twenty years into the future. At the end of those moments, when the world reawakens, all human life is transformed by foreknowledge.

Caitlin Decter is young, pretty, feisty, a genius at math - and blind. Still, she can surf the net with the best of them, following its complex paths clearly in her mind. But Caitlin's brain long ago co-opted her primary visual cortex to help her navigate online. So when she receives an implant to restore her sight, instead of seeing reality, the landscape of the World Wide Web explodes into her consciousness, spreading out all around her in a riot of colors and shapes.