Humanity is facing its greatest challenge. The alien Reivers have conquered our world, and their newly erected strongholds cast alien shadows across a subjugated land. Twenty years earlier, extraterrestrials first came to Earth. Small groups were abducted by these seemingly hostile entities, and stranded on a spacecraft they named the Keanu. However, these entitles journeyed here for help - against the Reivers who had overrun their home-world. But they'd carried their contagion to the stars, and brought the Reivers to us. So when Keanu finally re-establishes contact with earth, a terrifying picture emerges.

Reivers control the planet and are now preparing to destroy Keanu. Rachel Stewart, who grew up on the ship, is to head up a band of Earth's last freedom fighters in a final bid for victory. Their goal is to infiltrate a massive Reiver fortress. But, somehow, Keanu holds the key. If those onboard can't find it, humanity will be finished. And the galaxy will be next.