Plot
Shortly after returning from their adventure into the past, Red and Chloe hide Maddox Hatter's magic pocket watch in Wonderland's hidden royal vault. The next day, they begin to learn how their lives have changed as a result of their time-travel. Although Bridget, the Queen of Hearts, has been transformed into a kinder ruler, and Cinderella is now safe, the consequences of altering the timeline soon become apparent: Red now has a younger sister named Pink, while Maddox's son Max, who Red had originally grown up with in Wonderland, is now a VK. Meanwhile, Chloe has trouble reconciling the younger version of Cinderella that she met in the past with the older Cinderella in the present, due to their differing views on life.
It is revealed that a young Maddox witnessed Red and Chloe using the watch to return to the present, and became obsessed with finding the watch. This led Maddox down a dark path and ultimately forced Bridget to banish him and Max to the Isle of the Lost, where he succumbed to madness and became a villain. Maddox was allowed back into Wonderland after the Isle's barrier was removed, but he is still searching for the watch with the help of the Cheshire Cat's daughter Chessy, and intends to exact revenge on Bridget for imprisoning him. After discovering that the watch is now in Wonderland's vault, he captures Bridget, who manages to send a magic distress signal to Red. Maddox uses Bridget's magical cards to seize control of Wonderland, and begins searching for the vault.
After receiving Bridget's warning, Red and Chloe return to Wonderland to rescue her. They are accompanied by Pink, Max, Luisa Madrigal's son Luis, Robin Hood's son Robbie, Captain Hook's daughter Hazel, Dr. Facilier's son Felix, and Mr. Smee's twin sons Squeaky and Squirmy. Maddox detects the group's arrival and forces them to fight through several magical challenges, including an attack by corrupted magic flamingoes and an enchanted chess game. During the latter challenge, Red inadvertently uses Chloe as bait for a carnivorous flower in order to win the game, leaving Chloe deeply hurt and damaging their friendship. Chessy also manipulates several members of the group into arguing with each other. Red bonds with Luis, but her relationships with both Chloe and Pink become strained. Meanwhile, Cinderella learns of the teens' departure, so she uses a magic mirror from Bridget to sneak into the Wonderland palace in an attempt to rescue her, but Maddox captures Cinderella as well.
Max, wanting to prove that he is not like his father, leaves the group to try and steal Maddox's Oraculum, a device that they can use to bargain for Bridget's release. Chessy, however, uses the Oraculum to show Max the truth about how Red and Chloe changed the timeline, robbing the Hatters of their original lives, in which Maddox never turned evil and had a loving relationship with Max. Devastated, Max vows to exact revenge on Red, and creates a magic bracelet; he convinces an angry and hurt Chloe to put on the bracelet, which turns her evil. Max and Chloe enter the magic hedge maze around the vault, pursued by Red and Luis. After she is separated from Luis by the hedges, a remorseful Red finds a "treasure box" that, in the new timeline, she and Pink had placed in the maze as children, and acquires her new memories of growing up with Pink. When Pink finds Red, the pair reconcile, and Red accepts Pink as her sister.
With Pink's help, Red catches up to Chloe and Max as they reach the vault. Max explains that he knows about Red's actions in the past, and plans to use the watch to change history again and prevent Maddox from turning evil. Chloe steals the watch for herself, but Red talks her down; Chloe removes the bracelet, returning her to normal, and they reconcile. The two convince Max that trying to change the past again would be too dangerous, considering the damage that they accidentally caused on their first attempt. Max reluctantly accepts this, and Red throws the watch into a magic well where it disappears. The group then reach the castle and capture Maddox with help from Bridget and Cinderella. Red convinces Bridget not to punish Maddox and apologizes to him, admitting that she was to blame for changing his life.
With Wonderland saved, the heroes all celebrate together, and Red, Chloe, Pink, and their new friends look forward to the future. In the final scene, Pink finds a strange glowing object that she hides in her and Red's "treasure box", and Chessy warns the audience that the story is not over.
