High above the planet Earth, an alien probe appears and in an unspeakably horrific instant, releases a deadly blast that strafes the planet's surface, leaving a miles-wide, smoldering crater of destruction in its wake. Millions die in Florida, Cuba, and Venezuela, their lives blotted out in a blazing millisecond. Just as swiftly, the probe implodes and crashes on the planet surface, but the remnants provide no clue as to its origin. Who are the attackers, and what provoked them?

Aboard the Starship Enterprise(TM), Captain Jonathan Archer learns of the destruction. His ship is called home; it is uncertain whether its mission of space exploration will continue. But before Enterprise reaches Earth, Archer is abruptly kidnapped from the bridge by the time-traveling enemies he has encountered before. He finds himself aboard a Suliban vessel, face-to-face with his old nemesis, Silik, a high-ranking individual in a battle known only as the Temporal Cold War. Silik leads him to his master, a mysterious humanoid from the far future.

The humanoid claims that the attack on Earth was just a test; and the next attack will destroy Archer's home planet...unless he and the Enterprise crew stop it.

To do so, they must enter a region of space called The Expanse - an area so dangerous that no ship has ever emerged from it unscathed. Vulcan crews were driven to bloodthirsty madness, Klingon crews were anatomically inverted, their internal organs exposed outside their bodies...while they still lived. Many vessels were lost, never to be heard from again.

Archer faces the greatest crisis of his career: Should he believe Silik's time-traveling master, and expose his ship and crew to the perils of The Expanse, in hopes of saving Earth from destruction? And can he convince Starfleet Command and the Vulcan High Council to let Enterprise go to face her biggest challenge?