RIDE A MASSIF TO THE NEXT STAR SYSTEM.FIGHT THE ENEMY.REPEAT.It's business as usual for Parnell Shi-Sawahla and the crew of the United Earth Government Navy ship Sassafras. For more than two hundred years humans have been hitching rides into space on vast sentient mountain ranges called Massifs in an endless interstellar war between the forces of Earth and Mars.But the same unanswered questions burn behind every battle, every conquered world, every new colony.Why do the Massifs carry humans to the stars? Why do they help us export our wars? What's in it for them?Ship crews aren't supposed to ask these questions - and they definitely aren't supposed to speak to the all-powerful avatars piloting the mountains. But when Parnell's deputy, Kaz, is stranded on an enemy planet, he needs the Massif's help to rescue her . . . and that means figuring out how to talk to it.Nothing could ever have prepared him for what he learns of the secrets fuelling their voyages across the galaxy. The only certainty amidst the dread is that there is far more at stake than the lives of his crew.Military sci-fi meets cosmic horror in this epic space opera from the multimillion-copy bestseller behind many globally beloved fantasy series including The Old Kingdom and The Left-Handed Booksellers of London - unmissable for fans of Andy Weir and Pierce Brown.PRAISE FOR GARTH NIX'You are in for a treat' GEORGE R.R. MARTIN'One of the best world-builders' BRANDON SANDERSON'Nix sets the standard' LEIGH BARDUGO'I will never get enough' SARAH J MAAS'A swashbuckling adventure' JOE ABERCROMBIE'A world with the same four dimensional authority as our own' PHILIP PULLMAN