The prince is finally convinced that Anastasia is not the girl he danced with at the ball after Jaq and Gus along with the bluebirds show him the broken but put back together glass slipper broken by Lady Tremaine earlier. He hurries off to the ship where Cinderella has been placed for exile by order of Tremaine. They touch hands and he realizes that she's his true love. The prince asks Cinderella to marry him and she accepts. The plot of Tremaine and her daughters Drizella and Anastasia are exposed, but they escape by magic.
As she is preparing for her wedding, Cinderella is confronted by Tremaine who reveals herself and her new plan: Anastasia has been magically changed into an exact replica of Cinderella. Tremaine whisks Cinderella, Jaq, and Gus away with the magic wand. Trapped inside a pumpkin that has been changed into a carriage with a human Lucifer as its driver, destined to take Cinderella to her doom, she escapes with help from the mice, and they return to the palace where the wedding is being held. Anastasia, after learning of the importance of true love from the king and asked by Cinderella earlier if she truly loves the prince, and after many attempts(she had been practising saying `I do' for much of the movie), after touching the prince's hand, realizes that it's not true love, and that she can't go through with her mother's plans, finally finishes with "don't" just as Cinderella arrives.
The prince sees Cinderella and realizes that his bride is not his true love. Furious with Anastasia's sudden conscience, Tremaine and Drizella emerge from their hiding places. Tremaine uses the wand to change the king's guards into animals and is about to do the same to Anastasia and Cinderella, but the magic is reflected off the prince's sword, and changes the stepmother and stepsister into toads while transporting them back to their old home. Anastasia changes back to her true form, returns the wand to Cinderella who uses it to restore the fairy godmother, who gives Cinderella and the prince a new wedding and they are wed at last. Anastasia offers the king back his wife's seashell saying she doesn't deserve it, but he allows her to keep it telling her that everyone deserves true love.
Sometime during the credits, you see a portrait of Anastasia with the baker from Cinderella II, implying that this movie is set before Dreams Come True. An extra scene shows Tremaine and Drizella returned to their human forms, but now wearing Cinderella's old servant clothes to work as servants as punishment for their deeds.