The path of black rocks leads Rapunzel and her companions to the Big Tree, an ancient, magical place. They encounter the unpredictable Hector and discover the moonstone magic formula. Hector proves to be a dangerous adversary to the group and Rapunzel realizes that her only chance to save her friends is the uncontrollable Moonstone magic incantation.
- Mandy Moore as Rapunzel
- Zachary Levi as Flynn Rider
- Eden Espinosa as Cassandra
- James Monroe Iglehart as Lance Strongbow
- Jeff Ross as Hook Foot
- Paul F. Tompkins as Shorty
- Kelly Hu as Adira
- Jonathan Banks as Quirin
- Kim Coates as Hector
- The German version of the title in English is "The Power of the Moonstone".
- This is the fifth special, followed by Tangled: Before Ever After, "Queen for a Day", "Secret of the Sun Drop", and "Beyond the Corona Walls".
- The alternative lyrics version of "Healing Incantation" was sung by Rapunzel, and the spell activated a new magic of Rapunzel's hair.
- There is a flashback of Rapunzel when she still has short brown hair, and it happens prior to "Before Ever After".
- Cassandra wears a new armored outfit at the end of the episode.
- This is the third time the closing theme "More of Me" is not featured, the previous being "Secret of the Sun Drop" and "Queen for a Day".
- It is said by Eugene that it has only been 6 months since they left Corona.
- Cassandra sings her first solo in this episode.
- Adira mentions Varian and Quirin in this episode.
- During the chase scene as Eugene's half of the caravan runs off the cliff and on to Rapunzel's the chain Hector threw at it, Hector himself, and his rhino is missing.