Crash Bandicoot 2 - Cortex no Gyakushuu! [PSOne Books] Japan

After his defeat, Dr. Neo Cortex discovers the crystals that keep the world in balance. However, something is wrong: some of the crystals are missing. When the planets align, the chaotic flux created by the event will destroy the world. Cortex devises a plan to save the world by creating the Cortex Vortex.