Earth discovers abandoned star gates that lead humanity to a genocidal alien race, in this space opera trilogy opener by a Hugo and Nebula Award-winning author.

"The author of Maximum Light blends a taut story of survival and culture shock with a thoughtful exploration of the nature of humanity." -- Library Journal

Humankind has expanded out into interstellar space using star gates -- technological remnants left behind by an ancient, long-vanished race. But the technology comes with a price. Among the stars, humanity encountered the Fallers, a strange alien race bent on nothing short of genocide. It's all-out war, and humanity is losing.

In this fragile situation, a new planet is discovered, inhabited by a pre-industrial race who experience "shared reality" -- they're literally compelled to share the same worldview. A team of human scientists is dispatched -- but what they don't know is that their mission of first contact is actually a covert military operation.

For one of the planet's moons is really a huge mysterious artifact of the same origin as the star gates... and it just may be the key to winning the war.

"Kress's Sleepless trilogy proved that she was a serious writer, worthy of considered attention. Probability Moon only emphasizes that." -- Locus

"Twisty and compelling, brimful of ideas, with Kress's usual life-sized characters: top-notch work from a major talent." -- Kirkus Reviews

• We started tracking this book on January 14, 2014.
• This book was £4.57 when we started tracking it.
• The price of this book has changed 152 times in the past 4,497 days.
• The current price of this book is £1.59 last checked 4 hours ago.
• The lowest price to date was £1.59 last reached on May 7, 2026.
• This book has been £1.59 one time since we started tracking it.
• The highest price to date was £11.99 last reached on October 30, 2025.
• This book has been £11.99 one time since we started tracking it.
• This book is currently at its lowest price since we started tracking it.

• Science Fiction & FantasyScience FictionFirst Contact
• Science Fiction & FantasyScience FictionSpace Exploration

• Publication Date: September 16, 2002
• Text-to-Speech: Disabled
• Lending: Disabled
• Print Length: 319 Pages
• File Size: 25 KB