The stunning second book in the Black Heart series.

The Station, a city buried deep beneath the surface of a frozen, lifeless earth, is only months away from completing its centuries-long mission to return the planet to its original orbit around the sun.

Seventeen-year-old Trajectory Specialist Trainee Trudy Barnard is studying to join Mission Control, the elite group that control the earth's movement. Though she's a brilliant student, Trudy is haunted by her illustrious pedigree: granddaughter of Matt Barnard, one of the Station's greatest heroes, and daughter of Arthur Barnard, its most powerful figure.

Trudy discovers a snippet of code hidden in the trajectory software that would obliterate of the Station at the moment of Arrival. When Mission Control are unable duplicate her findings, she's accused of grandstanding, trying to grab attention. She's ordered to drop the issue, but Trudy will stop at nothing in her quest for the truth.

In a desperate race against time, and targeted for death by an unknown enemy, she struggles to unravel the mystery.

But can she unlock the secret in time to save them all?