Kaoru's father, Hideyuki, lies dying in a Tokyo hospital, his body ravaged by viral cancer. This nightmarish incurable disease has sprung out of nowhere and has begin to affect organisms all over the planet.

Twenty years ago, Hideyuki worked on a virtual reality project which replicated evolution on earth, called the Loop. The project failed when the organisms within it inexplicably stopped reproducing normally and started cloning. Nearly all of the scientists who worked on the Loop are already dead - from cancer.

To get to the heart of the mystery, Kaoru must travel to the other side of the planet, to the Mojave desert. The secret he encounters there will overturn everything he thought he knew about the world - and his own identity.

Loop is the sequel to Ring and Spiral. Translated by Glynne Walley.