An outstanding, highly original and unputdownable read! This is a bold, thought-provoking adventure perfect for fans of MORTAL ENGINES and THE LAST WILD. 'I loved every page of this gripping, dystopian thriller. Wonderful characters, thrilling action and a unique new world. Now I wish I had my own animal construct!' Kieran Larwood, author of Podkin One Ear 'I wolfed this down... Great MG sci-fi.'Darren Simpson, author of Scavengers Coll belongs to Wolf. He lives with his crew on a Construct, a huge technological 'creature' driven by the crew's combined willpower. Together they roam their world, fighting other Constructs and absorbing them into their own. But when a new and dangerous Construct attacks them, Coll is thrown clear from Wolf and left behind. Now he must survive life on ground and get back to his crew. He is helped by Rieka, a 'Tock' who makes the Constructs work. She promises Coll a way to return, but can she be trusted? And what is she really trying to do...? When Coll uncovers the truth, it destroys everything he thought he knew about Wolf, the world they live in, and even himself. In a world full of danger, and suddenly without meaning, can he find a way back?

Alastair is a children's author and puzzle creator. As a puzzle creator he wrote quite a lot of books of Sudoku and other puzzles for kids and grown-ups, and as an author he writes picture books and middle-grade fiction. Alastair lives in Edinburgh with his wife (who is lovely), two teenagers (who are lovely but very loud), and a cat named Maudie, who is yowling at him even though there is clearly food in her bowl, look, it's right there, look. His hobbies include writing and playing games on his phone when he should be writing. You can follow him on Twitter @alastair_ch, if you like.