Ario is a Cheat: somebody who designs and sells Cheat Codes to Gamerunners.Rick is - or was - a gamerunner: someone who tests there are no glitches or bugs in the Maze, the computer game that is so much more than a computer game. Then Rick's father falls out of favour and Rick is forced - jettisoned - out of the safety of his home on to the dangerous streets of Undone and the outside world - a world of flesh-dissolving acid rain and ferocious, feral, roving gangs. There Rick meets Ario and together they find a joint cause that will lead them into a terrifying and dangerous battle with Crater Inc., the shadowy, sinister and all-powerful company that created the Maze . . .