The Swan Princess: A Royal Myztery

The Swan Princess: A Royal Myztery is a 2018 computer-animated spy-themed musical comedy film produced by Crest Animation Productions and Nest Family Entertainment, directed by Richard Rich and starring the voices of Nina Herzog as Odette, Yuri Lowenthal as Derek, Jayden Isabel as Alise and Grant Durazzo as Lucas. It is the eighth film in The Swan Princess series. It was released on DVD and Digital HD on March 27, 2018.

Plot
Queen Uberta has written a book called "Queen U to the Rescue!" Where she details a (fictional) account of how she saved the kingdom from Count Antonio, and saw through his fake proposal for marriage. In the morning, she wakes up to find a "Z" slashed into the cover of her book, and Lord Rogers thinks she did it by accident with her long, sharp fingernails.

Alise and Lucas are staying in Borromeo, while Lucas and his family plant tulips for King Sebastian. Lord Rogers kept Antonio's submarine so he can make a blueprint of how it works and use it for good, but someone slashes a "Z" into the blueprint. Similar marks are made on Speed and Jean-Bob, and rats are believed to be making the marks.

Prince Derek and Princess Odette learn that they have both been marked also, and they go to the kingdom of Borromeo to make sure the children are all right. Puffin flies over the kingdom and sees another "Z" slashed in the tulip garden, and Scully's ghost reappears and reveals he saw a Man in Black on a rooftop spying on them, and whistle to command the rats. The rats chew through a chandelier that falls and almost hits Prince Derek, but Scully pushes him out of the way.

The kings guards tell Prince Derek that Nicolo, imprisoned, wishes to speak to him to reveal information about the Man in Black. Nicolo is revealed to have gone mad in his cell, developing a split personality, and obsessing over Queen Uberta's book. He warns Prince Derek that Count Antonio survived, and is back for revenge. Derek brushes this off, as Antonio sailed into a hurricane and no one could have survived.

Scully tried tracking down the Man in Black, but is being chased by the ghost of one of the Boggs, who wishes to capture Scully for helping the "pink bellies" escape the island while they were shipwrecked. Scully distracts them with a trial, and manages to escape and tell Puffin to get Rogers help. Lord Rogers has a glass jar used for holding a ghost, as glass is the only thing that can hold a ghost, as well as a ghost rope.

Odette decides to track the Man in Black by following the rats, with the help of Number 9 at the King's Assistance. She's almost lead into a trap, but realizes the trap was meant for Derek, and that all of this has been about Derek. When Derek falls into the same trap, he escapes when the King’s guards chase off the Man in Black. Derek learns that Antonio's last name was Zambrano, and that he really is back and is indeed the Man in Black, as Nicolo said. Derek warns King Sebastian.

Lord Rogers learns that putting something in his ghost trapping jar temporarily makes it transparent like a ghost, and puts gloves and trackers in it so he can track Scully and the Bogg ghost chasing him. With the help of Lucas and Alise, they get the tracker on him and are able to track him so Scully can find the Man in Black.

Derek and Odette visit Nicolo again, who warns them that Antonio is after the children, and they learn that the children are in fact missing. They go back to Nicolo's cell and find a hidden passage, that leads them to where Lucas and Alise are being held captive. Derek frees them but is soon captured himself, and Odette gets the children out before Nicolo reveals himself. He reveals to Derek that Antonio isn't really alive, he himself was the Man in Black all along, and the rats helped him mark Derek and his friends for revenge. He says Queen Uberta’s book helped him learn who all was responsible for his imprisonment. Derek asks him about the Z's, and Nicolo reveals they were actually N's.

The Bogg ghost manages to capture Scully, but Scully pleads with him to free him long enough to help his friends, with the promise that he'll return to face his punishment. The Bogg agrees, and Scully returns to find Nicolo holding Prince Derek on the dock. Princess Odette and everyone race to the dock, but are too late to stop Nicolo from trapping Prince Derek in a prototype for the submarine and dropping it into the sea.

Scully goes down into the submarine with Prince Derek, so Lord Rogers can give Derek instructions on how to make the submarine work. One of Nicolo's rats frees Derek from his binds so he can work the controls. Rogers instructs him to use a flat wrench as a make-shift lever to replace the one Nicolo broke off so Derek couldn't free himself. Derek starts losing air, and isn’t strong enough to pull the lever. The Bogg ghost returns, and scares the rat so it jumps on the lever, and the submarine floats up to the surface, freeing Derek.

Scully asks the Bogg for a chance to say goodbye, but the Bogg tells him he is free to go. Derek and Odette tell Queen Uberta that her book gave Nicolo the motivation for revenge, and she sees this as an opportunity to write a sequel.

Cast

 * Nina Herzog as Odette
 * Yuri Lowenthal as Prince Derek
 * Jennifer Miller as Queen Uberta
 * Joseph Medrano as Lord Rogers/Scully
 * David Lodge as Niccolo/Number 9
 * Jayden Isabel as Alise
 * Grant Durazzo as Lucas
 * Tobias Booker as Hunch/Nums