Rapunzel continues to try and restore the memories of her parents, King Frederic and Queen Arianna, and hopes to use the journal of Herz Der Sonne to remind them, but they do not understand the significance. Ariana still lusts for adventure while Frederic cannot get over his obsession of egg collecting. Rapunzel recruits her friends to try and set up the perfect date for them and while they cannot find anything in common personality wise, they share a mutual love for Rapunzel. However, King Trevor arrives with the intent to woo Ariana using an ocean crystal he found. Despite Rapunzel's attempts to keep him away, he manages to convince Ariana to join him in watching the sea serpents. Rapunzel realises that the ocean is lawless and Trevor will attempt to marry Ariana out there. Rapunzel and her friends manage to catch up, but Trevor sends his "navy seal team" to attack them. Ariana fights back and tries to rescue Rapunzel, Frederic and their friends from a sea serpent. Eventually, Frederic realises that the ocean crystal is, in fact, a sea serpent egg and gives it back. Trevor, who gives up after seeing how much Frederic and Ariana care for each other, gives back the journal that he stole, but it is water logged. Rapunzel makes a new journal that she and Eugene sign and Frederic and Ariana both begin to remember their lives when they were young.
- Mandy Moore as Rapunzel
- Zachary Levi as Eugene Fitzherbert
- Clancy Brown as King Frederic
- Julie Bowen as Queen Arianna
- Bradley Whitford as King Trevor
- James Monroe Iglehart as Lance Strongbow
- Jeremy Jordan as Varian
- Vivian Vencer as Angry/Kiera
- Paul F. Tompkins as Shorty
- Steve Blum as Attila
- Charles Harlford as Vladimir
- The serpent, which was portrayed in Corona's map from the credits of Tangled, appears in this episode.
- King Trevor's Navy Seals is a nod to the special operations force of the United States Navy.
- The title references the King of Hearts and the Queen of Hearts.
- It's revealed that Queen Arianna has a thirst for adventure, and King Frederic likes collecting eggs.
- This is the second episode that takes place during the annual Day of Hearts celebration, the first being "Under Raps".
- It's revealed that King Frederic is unable to swim.
- Herz Der Sonne's journal is destroyed in this episode.
- It's revealed that Maximus's copy of the Corona law book still has the dagger stabbed on the cover since the events of "Max and Eugene in Peril on the High Seas".
- There are a few scenes that are references to the original film.
- Rapunzel's line "Garçon, your finest table, please" is a reference to Eugene's line when he brings her to The Snuggly Duckling.
- During King Frederic and Queen Arianna's date out on the lake, Eugene makes a reference to his and Rapunzel's first date in "I See the Light".
- Rapunzel knocking out King Trevor and tying him up in her hair is a reference to her actions when she first met Eugene.
- It's revealed that King Frederic and Queen Arianna still have amnesia after their memories were erased in "Rapunzel's Return", and Varian has since been trying to find a cure to restore them.
- By the end of the episode, their memories slowly begin to return after they witness the love between Rapunzel and Eugene.
- It's revealed that Rapunzel and Eugene still have yet to write their names in Herz Der Sonne's journal which becomes a running gag throughout the episode as Eugene expresses his wish for them to sign the book together.
- By the end of the episode, after Rapunzel creates a new Book of Hearts, she and Eugene are the first to sign their names.