The Legend Begins is the seventh episode of Season Three.
Haggar tries to wake Zarkon, but only ends up looking onto glimpses of memories of the past when he was a Paladin.
The team attempts to figure out Lotor's plans, as the comet they found bears similar elements as their Lions. Shiro suggests that learning the history of the Lions will help them understand the situation. Allura is reluctant to tell more, so Coran tells the team the story on her behalf.
The original Paladins began as leaders of their respective planets who came together to bring peace and later became friends.
The paladins are introduced while on a peace mission. Alfor rushes into battle alone, only to be surrounded and outnumbered. Zarkon, Trigel, Blaytz, and Gyrgan come to his aid. Later, at an official dinner on Zarkon's home planet of Daibazaal, the group is talking when a comet crashes. After evacuation of the area, Alfor begins to research the comet and quickly learns of its ability to travel through alternate realities. Unfortunately, it already created a trans-reality rift by the time the comet is removed and studied. An Altean alchemist, Honerva, leads the investigation on the rift, while Alfor researches the comet's core back on Altea.
Years pass and Zarkon marries Honerva, while Alfor visits occasionally, even bringing his daughter with him. During this time, Alfor begins to create ships from the comet, and Honerva learns about Quintessence and how a single drop can power an object for extreme amounts of time. She also sends signals into the other reality, prompting a rift creature to cross through realities, requiring containment. Alfor becomes angry at Honvera because she is not being careful in her investigation. At that moment, more rift creatures emergy and begin to cause damage, but they are quickly contained in a particle barrier. However, it is unable to hold for long. Alfor's project is the only thing that can save the planet.
Alfor takes Zarkon and the others to see the ships he's been making - the lions. He explains how each lion is different and how he felt a psychic link with his lion while testing it. The lions' powers will become unlocked over time.
With little time to spare, the new Paladins fly to Daibazaal to fight the creatures right as they break through the barrier. The Lions' attacks are not hitting. Alfor gets the feeling of needing to go into a formation. The group then forms into a giant robot, which Alfor christens Voltron, and defeats the creatures.
Alfor wants to seal the rift to avoid a repeat of the events of the attack, but Zarkon decides to keep it open so that Honerva can continue her investigations. The Paladins still travel through the Galaxy maintaining peace and bringing a new age of exploration. At this time, Voltron becomes known as the Defender of the Universe.
Time passes and the planet of Daibazaal does not look as healthy as it used to. Alfor visits to see how the planet is holding up. Zarkon is unwilling to leave the planet due to Honerva's research. While talking to Honerva, Alfor notices that her cat, Kova, looks different. He learns that the cat fell ill and Honerva treated it with Quintessence. Honerva is hostile to anything that Alfor says and her Altean markings have turned into red lines. Zarkon talks of ruling the universe, using Voltron to travel through the rift, and living forever. Alfor leaves, wanting nothing to do with his plans. After he is gone, Honerva faints.
Back at Zarkon's place, Honvera speaks about Quintessence and entering the rift with Voltron. Zarkon tells the other Paladins that his wife has fallen ill and that his planet in nearly in pieces. He wants them to help him close off the rift. They all agree to help.
Using Voltron, they enter the rift and Zarkon's true plan shines through. He and Honvera leave the Black Lion and float in pure Quintessence. The rift creatures return and Voltron makes its escape. After leaving the rift, they find that Honvera and Zarkon are dead due to overexposure of Quintessence.
Alfor evacuates the planet and gets rid of the rift by destroying it. He holds a funeral for Zarkon and Honerva. However, they both come back to life and learn that their planet not longer exists. Zarkon then takes revenge by destroying Altea in the war, but not before Alfor could send the lions away to the farthest corners of the universe.
Now that the group knows the true purpose of Lotor's plans, they become more eager to stop him. Meanwhile, Haggar remembers her past and Zarkon opens his eyes at her plea for him to come back to her.
- The origin story of Voltron and its Paladins was originally planned to be the first episode of Season Two, but was put off for later out of fear that it would be too much information too soon. This allowed Haggar's Altean heritage to be revealed in the Season Two finale instead, and a natural progression from the reveal of Voltron's trans-reality ore into its full origins.
- The helmet given to Allura by Zarkon when she was an infant is intentionally modeled after the helmet worn by Lotor of Defender of the Universe.