The Swan Princess: Escape from Castle Mountain (alternatively known as The Swan Princess: The Secret of the Castle in European countries) is a theatrical sequel to the animated film The Swan Princess. Directed by Richard Rich and released in 1997, the film follows Derek and Odette's one-year anniversary of their wedding being disrupted by the actions of the wizard Clavius, who wants to regain the Forbidden Arts and destroy their happiness. The film was followed by two more direct-to-video sequels: The Swan Princess III: The Mystery of the Enchanted Treasure (1998), and The Swan Princess Christmas (2012).
Most of the main voice cast of the previous film has been replaced, save for Michelle Nicastro, who reprises her role as Odette and this time did her own singing, and Steve Vinovich, who reprises his role as Puffin. This sequel features recycled footage from the previous film, most notably in the flashbacks during "The Magic of Love" sequence. Musically, the film also samples the soundtrack of the previous film, such as during the scene where Clavius is changing Queen Uberta into various animals; the instrumental of "Practice, Practice, Practice" can be heard. Overseas production for all three films was by Hanho Heung-Up Co., Seoul, South Korea.
It has been one year since the events of The Swan Princess. It is Derek and Odette's anniversary, but Derek has forgotten this as he is busy setting Swan Lake Castle (which has become his and Odette's new home) up for the arrival of a royal guest, the King of Lincolnshire. The evil Knuckles sets a trap for Derek and sets the fields on fire. Derek goes to stop him while Speed, Puffin, and Jean-Bob try to slow Knuckles down; Knuckles knocks Puffin into a tree and sprains his tail, but Derek survives Knuckles's trap.
Knuckles reports to his master, the wizard Clavius who resides in a dormant volcano. Clavius was once Rothbart's partner who helped him conquer the Forbidden Arts, but Rothbart betrayed him and drove him underground. Clavius intends to kill Derek so he can take the Forbidden Arts, which are hidden inside Swan Lake Castle.
To make up for forgetting Odette's anniversary, Derek plans to take Odette on a picnic, however, when Lord Rogers finds clues about Knuckles, Derek abandons both the picnic with Odette and Queen Uberta's birthday to look for him. On Uberta's birthday, she is abducted by Clavius, who sends Derek a ransom note as part of his next trap.
After ordering Knuckles to kill Derek with more traps, Clavius sneaks into Swan Lake Castle where he locks Odette in a tower and goes after the orb containing the Forbidden Arts. However, Bridget, Rothbart's former accomplice who joined the side of good, takes Speed, Puffin, and Jean-Bob into the catacombs and they find the orb. When the four enter Odette's tower, Odette knows that Derek is heading into a trap. As Puffin cannot fly because of his injured tail, Odette has Bridget transform her into a swan, and she flies away to save Derek just as a furious Clavius arrives. Clavius chases after Bridget, Puffin, Speed, and Jean-Bob in an attempt to steal the orb, ending with Clavius smashing into a wall and Speed, Jean-Bob, and Puffin entering the water-filled dungeon of the castle with the orb.
Derek overcomes most of Knuckles's traps, but eventually Knuckles sends him falling into a pit of quicksand, from which he is rescued by Odette.
Clavius steals the orb from Speed, Jean-Bob, and Puffin and knocks Bridget into the dungeon, but Jean-Bob gets them out with a chain and the three animals grab onto Clavius's hot air balloon as he returns to his volcano. Upon arrival, Clavius absorbs the power of the Forbidden Arts, giving him the power to create, change, and destroy. As Derek and Odette make their way to rescue Uberta, Knuckles attacks Derek. In the fight that follows, Knuckles thinks he knocked Derek into the lava pool beneath the volcano (though Derek grabs a vine to break his fall), ties up Odette, and rides a basket towards the volcano. When Knuckles drops Odette over the edge, Derek cuts the rope holding the basket up and saves Odette while sending Knuckles falling into the lava.
Entering the volcano, Derek fights Clavius while the animals free Uberta from her prison. When Clavius is about to kill Derek, Jean-Bob jumps on his head, and Clavius kills him. Derek takes the orb, preventing Clavius from using his power on him, and intends to destroy it once he turns Odette human again. As Derek and the others fly Clavius's balloon out of the volcano, Clavius tries to stop them and take back the orb. Derek knocks him over the edge, but accidentally drops the orb, which explodes on impact with the ground, causing a volcanic eruption that kills Clavius.
With the orb gone, everyone goes to Swan Lake, where the moonlight turns Odette back to her human form and revives Jean-Bob. After they celebrate their victory and Uberta's fiftieth birthday, the King of Lincolnshire arrives, but Derek tells Rogers to take care of it while he spends the day with Odette.
- Michelle Nicastro - Princess Odette, the main deuteragonist
- Douglas Sills - Prince Derek, the main protagonist
- Christy Landers - Queen Uberta; the tetartagonist
- Donald Sage MacKay - Jean-Bob the frog; one of the three tritagonists
- Doug Stone - Speed the turtle; one of the three tritagonists
- Steve Vinovich - Puffin; one of the three tritagonists
- Joey Camen - Knuckles; one of the two main antagonists
- Jake Williamson - Clavius; one of the two main antagonists
- Joseph Medrano - Lord Rogers
- James Arrington - Chamberlain
- Owen Miller - Bromley
- Rosie Mann - Bridget the Hag
- Campbell Morton - Alligators, Wolf
- The Magic of Love
- That's What You Do for a Friend
- You Gotta Love It
- Far Longer Than Forever (end credits)
- No Fear (rap)