In the year 2050, Earth makes first contact. By 2052, the war is over. We lose. Soon after the generation starship Pioneer leaves Earth's orbit, the ship is struck by a rogue asteroid. At first, Captain Tyson Grant believes the accident is minor. But when a by-the-book investigation of the damage ends in disaster, he realizes he was wrong.

Two hundred years ago, aliens invaded Earth. A violent war followed. The enemy won. Some of us escaped, most of us didn’t. On Proxima they flourished - the invasion forgotten. On Earth we floundered - the horror began. Their world is advanced, peaceful, and secure. Our world is broken, savage, and overrun. A new invasion is coming. A hunger that has swallowed half the universe. They don’t care which planet we live on. They want to end us all. But where there is life, there is hope. And where there is hope, there are heroes. This time, vengeance will be ours.

The invaders are gone. Earth is in ruins. The strong prey on the weak. In the wastelands of what’s left, a lone gunslinger delivers his own brand of justice. Some call him lawman. Some call him madman. Some call him vigilante. Some call him killer. Some call him legend. They all call him...the Sheriff. This is his story.

The enemy is coming. The enemy is already here. For years they’ve prepared, plotted, and planned. For years they’ve waited to strike from above and below. Earth is under siege. The enemy covers the landscape. Proxima is unharmed. But that’s about to change. No armies can stop this menace, and no defenses can slow the advance. We are scattered and isolated. We are ignorant and weak. No help is coming. No help remains...or does it? Old heroes will sacrifice everything. New heroes will rise.

As a development platform for desperately needed advanced technology, the experimental starship Foresight is the greatest hope humankind has to flee the alien hordes. For test pilot Captain Nicholas Shepherd, the success of the program is even more personal. Successful completion means delivering his wife and son safely off-world and leaving the war behind for good. But when Foresight suffers a critical malfunction during her final scheduled flight, what should have been a minor setback becomes a major fight for survival.