The evil Prince Lotor of Planet Doom has come to destroy Planet Arus and take Princess Allura to be his slave. The Voltron Force, Keith, Lance, Pidge and Hunk pilot the Black, Red, Green and Yellow Lions to defend the peacful planet. With Princess Allura in the Blue Lion, they form Voltron and destroy Lotor's robeasts. Frusturated, Lotor targets Planet Pollux, and Allura's cousin Romelle. Can Voltron defend two entire planets at once? And what will happen to the Voltron Force after a poisoned blade leads to Princess Allura's funeral?