In the 23rd century, five space explorers are sent to a distant planet in the far universe, in hopes to aid the leaders in their fight against the evil forces of King Zarkon. Captured by a Doom Slave ship, Keith, Lance, Hunk, Pidge and Sven, escape to Planet Arus, where they meet Princess Allura, the sole survivor of the once great royal family of Altaire. Her father, King Alfor, had created a great defender; a giant robot called Voltron, who once protected Arus from the onslaught of King Zarkon and his robot fighters. Together, they discover the secret to form this mighty defender, to protect Arus and its people from the tyranny of King Zarkon, and his son Prince Lotor.