One of the best brain doctors of his time, Nathi lost his own brain five centuries ago when he became a posthuman. He is now called upon to save a comatose girl. The damage is extensive, so he decides to map his own mind into her brain in order to replace the damaged part. But something unexpected awaits him within the girl’s brain. She is a carrier of a Wish Fairy, an enigmatic sentient cyberbeing whose only purpose is to kill the Wish, a virus used to enslave all posthuman minds, including Nathi’s. Liberated, Nathi forms a symbiotic union with the girl, discovers the true cause of her brain injury, and finds a way to break out of the Castle, their high-tech prison, and into the Martian polar night. But once outside, the real chase begins. It is a battle that must be fought both in the physical world and that of the mind.