Nicholas, the two-faced ruler of the Zinba Empire, wants more territory and means to make Earth his personal colony. His scheme begins with wiping out the city of Orion to strip the planet of its defenses. A group of young people on holiday on Mars learn of the devastation back home and realize how much danger they are in. In an underground cave they meet Dr. Han and Fred. Dr. Han is convinced that an immortal bird called the Phoenix King, said to guard the Earth, lives somewhere on the planet and is the only power able to stop Nicholas. The young travelers set out for the creature's rumored home, a science fiction action film with mecha elements.