Carpathia awaits the arrival of what could be the last transporter from Earth. Loyalties are tested as the head of Forthaven's Expeditionaries attempts to break away from the settlement, and the beginnings of a mystery which goes right to the heart of human life on Carpathia are uncovered.

News of a missing survival shuttle sends Cass, Fleur and Jack outside the settlement in search of Stella's daughter, only to find that something or someone has got there first. Stella and Tate are confronted both by their old foe Julius Berger and the accusations made against him by a young woman from the transporter.

A whiteout of unprecedented strength threatens to destroy Forthaven. Stella and Tate enlist Tipper to help with the oncoming disaster. Fleur attempts to make peace with the ACs, and Cass leaves the settlement on a rescue mission that no one believes he can survive.

When a rogue AC enters Forthaven and attacks a citizen, Cass and Fleur must control the situation. But Fleur soon finds herself calling into question everything Forthaven stands for and Cass must make an agonising decision.

Patrick Baxter, a Carpathian legend, long thought dead, arrives back in Forthaven with a fist full of diamonds and stories of 'bodies' outside the settlement. Cass and Fleur find themselves in grave danger as they follow Pak into unexplored zones of the planet, whilst back in Forthaven Tate must deal with Berger's growing power base and the appearance of his own dead children.

When missing expeditionary Josie Hunter walks back into the settlement, unharmed, the jubilant air quickly takes a darker tone. Josie is different, her children cannot communicate with her, and reports of her violent behaviour circulate. Tate and Stella must find out what is behind this changed Josie, and begin to come to terms with what is really at work on the planet.