Alyssa Wright is about to lead the most ambitious space exploration mission in history: a one-way journey to Mars.But two weeks out from launch, she is horribly injured.Left behind on the planet she’d hoped to escape for ever, Alyssa becomes obsessed with the ongoing Mars One mission and uncovers what she believes to be a conspiracy that could put the very lives of her crew at risk. Meanwhile, on the other side of the planet, a young coder goes missing, leaving behind a cryptic message for his sister, Jia: destroy my hard drives, protect my cat.Forced to flee the violent forces pursuing her, Jia realises that her brother must have uncovered a dark, dangerous secret – and now, Jia is the only person who can save him. At the same time, millions of kilometres away, as the Argo continues to race towards Mars, the crew must grapple with the emotional fall-out of leaving the rest of their species behind.But when small mistakes and minor malfunctions turn into a disastrous spacewalk, they are forced to ask themselves a terrifying question: is there a saboteur on board?These three strands collide in a breathless, edge-of-your-seat thrill ride that takes the reader from the besieged city of Hong Kong, across the plastic-choked waters of the North Pacific Gyre, to the barren plains of the Kazakh Steppe, and out into the depths of space, asking: what is the cost of human progress, and are we willing to pay the price?