On the beach of Nueva Vista, everyone is getting ready to celebrate Dia de los Muertos by building their alters. Marzel shows up and Elena explains the holiday to him, including how in Nueva Vista they put their altars on boats after building them and sailing them out to sea. Elena then takes Marzel to her family's altar. When he sees the pictures of King Raul and Queen Lucia, Marzel asks Elena if those are their parents which Elena confirms. Elena also adds that her father loves cherries and Isabel adds that her mother loves sweet bread. Luisa asks Elena if she's seen her grandfather. Just as she replies she hasn't, Elena sees Francisco walking behind some rocks carrying a huge chest. Elena and Marzel go over to see what he's doing. Upon meeting up with him, Elena tells her grandfather he shouldn't be carrying something like that. Francisco tells his granddaughter that being old doesn't mean he's incapable. He also explains that he's making an alter for some friends of his who died in a shipwreck. After assuring Marzel that it wasn't the Sirenas fault, Francisco explains that it's his fault. Francisco explains that he was steering a ship with them aboard when it suddenly capsized. Suddenly the spirits of his friends suddenly appear before Elena. Francisco and Marzel wonder who she's talking to. Elena explains that she can see the spirits of those who have moved on on Day of the Dead and proves it by telling her grandfather that El Guerrero and El Místico say hi. Francisco tells them he happy to which they say they are happy to see El Capitán again. When Elena questions the use of these codenames, Francisco explains that when he and friends would go out and risk their lives for everyone in Avalor as Los Tres in secret, it was forbidden for men of his class to risk their lives for any reason. This ended when the incident that he mentioned earlier happened.
Elena tells Francisco she never knew he was such a hero. Francisco tells her that the mission that they were on when he lost his friends is the only one that they didn't finish. Francisco tells them they were trying to find El Escudo, a magical shield that can block any magic so that the Macoco couldn't get it. Marzel explains that the Macoco is a two-headed ocean beast who attacked Avalor years ago. Francisco takes it from there and adds that the then Royal Wizard stopped it. He also adds that the Macoco has been seeking El Escudo ever since. El Guerrero and El Místico explain that they want to complete the mission. Francisco agrees and Elena decides to allow it if he promises to be careful.
Out to sea, the group arrives at the spot where his ship sank. Marzel offers to dive down and get the map. Francisco refuses on the grounds that this is a matter of Los Tres. Marzel accepts his decision and, after returning to his Sirena form, returns home. El Guerrero and El Místico are shocked that Marzel is a Sirena, to which Elena explains that the Sirenas are their friends now. Francisco decides to dive down and get the map, despite Elena's objections. Fearing for his safety, Elena goes after him. Under the sea, it turns out that Elena needn't have worried when Francisco gets the map all by himself. Upon meeting up with Elena, they return to the ship. After they set sail again, the Macoco surfaces and decides to follow them.
The group arrives on an island and, using the map, find the shield inside a cave. Francisco pulls it out. Francisco tells Elena to pull out her Scepter but Elena insists on helping him carry the chest the shield is in. This proves to be a mistake when they get back outside when they get ambushed by the Macoco, who reveals that they sunk his ship all those years ago and steal the shield. Francisco temporarily loses faith in himself but El Guerrero and El Místico help him regain his confidence. Francisco retrieves the shield and Elena blasts the Mococo away with her Scepter. The group the heads back. On the way, Los Tres gives Elena the code-name La Magica. Then they arrive back at the beach, Francisco tells Luisa he and Elena were getting Marigolds for the altar and the Royal family sends their altar out to sea. Elena apologizes to Francisco for underestimating him and Francisco tells her that they are Los Quatro from now on.
- Aimee Carrero as Princess Elena
- Emiliano Díez as Francisco
- Jorge R. Gutiérrez as El Guerrero
- Freddy Rodriguez as El Místico
- Rob Paulsen as Macoco
- Prince Royce as Prince Marzel
- Julia Vera as Luisa
- Jenna Ortega as Princess Isabel
- This is the first Dia de los Muertos episode where King Raul and Queen Lucia's ghosts don't appear.
- Moral: Everyone is useful no matter how young or old they are.
- It is possible that it was named after the DuckTales character or the movie theatre.