Five space explorers are captured by and escape from the evil King Zarkon's forces.
Five earthborn space explorers approach Planet Arus, only to find it under attack by Zarkon's forces.
The crew wants to help, but they are too late. As they survey the ruins, they are picked up by one of Zarkon's mop-up ships.
Back at Galaxy Garrison, a group of officials review the events and discuss
a rescue mission, dismissing the idea due to the fact that "Zarkon's planet is over 2,000 light years away" and thus impossible to reach in time. They note that Zarkon's ambassadors deny any knowledge of an attack
on Arus. Marshall Graham recounts that the legendary Voltron originated on Arus...
"Voltron could save them."
On Yurak's slave transport ship, an underling announces that the space explorers will soon be aboard. Yurak is pleased.
In Castle Doom, Zarkon celebrates the conquest of Arus and boasts that the capture of the space explorers means he no longer needs to fear the Galaxy Alliance (his reasoning for this is not exactly spelled out). Haggar warns that Arus' Castle of Lions holds the secret of Voltron, and that Zarkon must beware should it be discovered. Zarkon dismisses this concern, secure in his faith in the strength of his robot gladiators.
Soon Zarkon joins the well-dressed Drule crowd in the arena, where a blue robeast is pitted against nearly nearly 20 slaves armed with swords. The crowd cheers as the robeast easily defeats all of them. He announces that the space explorers are next!
The space explorers wait in their cell, dreading their turn in the arena. They are running out of time! Suddenly, Pidge suggests that if Hunk can bend the bars on the window, perhaps they'll have a way out. With Lance and Sven on lookout, Pidge leaps to the window and drops a rope for Hunk, who climbs and bends the bars wide. The team scrambles up and out.
Part way down, they are attacked by the alien vultures; the team grabs the birds and hangs on for a faster ride down. Landing more or less safely in a pile of bones, the team races for the arena building, which doubles as a hangar for the slave transport ships.
The team sneaks in via a utility tunnel. While they walk the corridors, an alarm sounds, and security doors start to close. The team narrowly makes it through a closing door into a room where they must immediately dodge a deluge of thrown swords. A melee ensues; the team defeats a squad of Doom soldiers, but more are coming. The team runs into a slave ship and takes flight.
Back in the royal throne room, Yurak notifies King Zarkon of the escape. Zarkon is angry, and commands Yurak not to return until he has recaptured them. Yurak launches his ship.
A firefight erupts in space between the commandeered slave ship and Yurak's assault vessel. The team returns fire, but the ship is badly outgunned and takes heavy damage.
The damaged slave ship falls toward Arus. Keith observes that some force is guiding the ship down smoothly, and Sven notes that the force appears to be emanating from a lion statue located in front of a mysterious castle. The team wonders if that is the Castle of Lions, where the secret of Voltron is hidden.
Keith quickly recounts the legend of how the formidable heroic robot Voltron was finally defeated: Zarkon's witch Haggar, disguised as a beautiful goddess, placed a curse on Voltron. She couldn't destroy him completely, but broke him apart into five robot lions.
Keith proposes that maybe the team can find the lions and reactivate Voltron....
The footage of Arus' destruction is repurposed; in Beast King Golion, it was scenes of Earth's World War III. It is also edited to remove images of screaming people disintegrating in the wake of atomic explosion.
Golion's god/dess of the universe is portrayed as Haggar in disguise.
Nearly every scene with slaves was edited to remove scenes of whipping, torture, dismemberment, and outright slaughter, especially in the arena battle scene.
During the escaping explorers' melee with Doom soldiers, the battle ends while Keith is still grappling one of them. This is because in the original Keith impales this soldier with his own sword in a rather gory fashion.
The first panning shot of the Castle of Lions shows two distant figures standing on the balcony. There is an immediate cut to Keith's story of the origins of Voltron, yet in the original BKG episode one is treated to closer shots revealing the two figures to be Coran and a regally-dressed Princess Allura.
Notes and Goofs
Hunk and Keith are in Dairugger uniform and in separate cockpits in the opening scene, but shortly thereafter are somehow in street clothes (as are the rest of the team) and together in one chamber.
The ending credits of this episode are shorter than those of subsequent ones, not panning through the various pilots atop their lions. This could have been done to increase suspense in new viewers, who otherwise would have discovered too early not only which space explorer pilots which Lion but also that Princess Allura pilots the Blue one.