Voltron: Defender of the Universe

On the way home from their latest mission, Hunk spots a planet that is home to some friends of his. He had met these kids on one of his first missions right out of the Space Explorer Academy. Hunk decides to take a vacation and visit them. Haggar and Cossack see a golden opportunity to isolate the Yellow Lion. They arrive on the planet and take the kids hostage. Cossack gives Hunk and ultimatum: Hand over the key to the Yellow Lion, or the kids have had it!