May Knox floats in space, the only survivor of a catastrophic accident. There is just one person who can save her: a man whose heart she broke, millions of miles away.

It's Christmas Day, 2067.

Silent Night drifts across the ruins of a wrecked spaceship, listing helplessly in the black. A sole woman, May, stirs within - the last person left alive of a disastrous first manned mission to Europe, a moon of Saturn.

There is only one person who can help her - her ex-husband Stephen, a NASA scientist who was heading up the mission back on Earth. Until, that is, she broke his heart and he left both her and the mission.

Now May clings to life and it is only his voice travelling across the fathomless miles that can bring her home.

In this twisty, gasp-inducing thriller, when each breath is a fight for survival, their relationship is the difference between life and death.