The Sirenas and humans meet at the beach. A woman is excited to see Prince Marzel and a sirena finds him equally amazing. Prince Marzel still has trouble walking. Marzel flirts with some of the girls. Elena comes by and wants to teach Marzel how to play discus, because the prince requested to learn more about humans. They start playing, and it soon turns out that Marzel is not used to his legs yet and often falls when trying to catch the discus. A carriage arrives and Marzel is fascinated by it. Elena invites her friend to take a ride to the palace with her. There she has to finish her planning on the Royal Retreat. Elena explains to Marzel what a Royal Retreat is and Marzel laments that his father is not going to come. Elena gets the idea to invite King Pescoro and together, Elena and Marzel travel to Coronado. Suddenly, Ocho alerts the prince that the king of the sirenas is in trouble. He has gotten stuck in a shipwreck with his tail trapped underneath some barrels. Elena and Marzel manage to free him just as the shipwreck collapses. However, King Pescoro hurt his fin and cannot attend the Royal Retreat. Elena suggests Marzel should go in his place. The prince is sceptical at first but King Pescoro encourages his son to go and Marzel accepts. He will now represent Coronado. He proudly tells Cuco who is not really sure because the retreat will be on land. Because of Cuco's talk, Marzel believes he has to act more human and goes on to prepare for the retreat by buying human clothes and working on his legwork.
The next morning, Elena greets King Joaquin, King Lars and King Raja at Nueva Vista. She announces their special guest, Prince Marzel, but the other rulers react with fear as soon as Elena informs them Coronado is the kingdom of the sirenas. Elena calms them down and they agree to meet Marzel. The prince of the sirenas arrives, not by swimming but with a carriage to Elena's surprise. Marzel introduces himself with a weird accent and tries to act human, even though it seems weird on him. Elena talks to him and asks why is acting so strange instead of being himself. Marzel says he wants to make a good impression. The Royal Retreat begins. Elena suggests staying at the Palace to play chess because of Marzel's problems with his legs but he insists to take part in the other king's favorite hobbies. They begin with horseback riding, Lars' favorite activity. Marzel is not sure about riding horses afterwards but brushes it off. They get on their horses. Marzel gets on his horse too, only the wrong way around. The horse throws him off and Raja catches him just in time. Marzel is embarrassed. They move on to play Olaball. This time Marzel has trouble because the game involves kicking and running which he has not mastered yet. It ends with him hitting the hoop with one of his shoes. They proceed with Raja's favorite thing to do. To Marzel's horror, it is rock climbing. Raja climbs up the cliff very fast. Marzel is determined to try, even though Elena does not think it is a good idea. Marzel forgets the safety rope and ends up falling. After another failure to do things right, Marzel leaves frustrated and tells Elena he is going home. Elena encourages him to be himself and Elena and the kings follow him to Coronado. He hands them the magical kelp and they wrap their chests. Marzel informs them if he were to wrap their legs too, they would all turn into sirenas. They dive into the water and swim to Coronado. Cuco meets the kings and they enjoy their stay. Marzel wants to show them the milagra forest where the magical kelp grows against Cuco's advice. They follow Marzel anyway.
At the forest, Marzel grabs the kings by their hands and swims very fast through the magical kelp. Suddenly the kings' legs are stuck and they turn into sirenas. Everyone panics and they swim to the palace to ask King Pescoro for advice. The kings have trouble using their new fins. King Pescoro is shocked and angry with his son but he does not know a cure. Marisa on the other hand comes up with the idea to use a flower that is said to reverse the transformation. They have to find the flower before the kings' tails stop glowing and the flower in question only grows on a certain far away island. Marzel does not think they can reach the island in time and swims away. Elena follows him and tells him he has to act like a true leader and be himself to find a solution. He comes up with the idea to build an underwater coach, drawn by Cuco.
The group reaches the island in time, but the flower grows on top of a cliff next to a waterfall. Elena goes to grab the flower, but she loses her footing and and falls to the ground, twisting her ankle. Now it's up to Marzel to get the flower in time. Marzel starts climbing the cliff while Raja tells him where to put his hands and legs. The prince of the sirenas manages to reach the flower. Then he jumps down the waterfalls to hand the flowers to the kings who then eat them. King Raja, King Lars and King Joaquin get their legs back and are happy about that. Marzel reports to his father and the kings commend Marzel on his bravery which makes King Pescoro proud. Marzel and the others spend the next day of the retreat playing discus.
- Aimee Carrero as Princess Elena
- Prince Royce as Prince Marzel
- Gina Rodriguez as Princess Marisa
- Edward James Olmos as King Pescoro
- Echo Kellum as King Joaquín
- Aasif Mandvi as King Raja
- Jeff Bennett as King Lars
- Travis Willingham as Cuco
- Richard Horvitz as Ocho
- Elena sprains her ankle when she loses her footing and falls off the rock wall, and cannot stand up due to the pain. Yet she walks to the boat with no visible limping or struggling. She is even surprisingly capable of playing frisbee in the final scene of the episode.
- King Raja and King Lars make their second appearance in the series since season 1's "Royal Retreat".
- Before the song, Cuco tells Marzel, "You gotta be part of their world", this being a reference to the song "Part of Your World" from The Little Mermaid.
- Moral: It's most important to be yourself to impress others.