Disney Channel has set Under the Sea: A Descendants Story, a new live-action short-form special for premiere on September 28. Descendants stars Dove Cameron and China Anne McClain reprise their roles as Mal and Uma, respectively in the special which features the arch-nemeses facing off in an epic underwater showdown.

In the story, Mal emerges from the shadows of a mystical forest onto a dark coastline where she crosses paths with Dizzy, played by Anna Cathcart. Descendants 2 stars Thomas Doherty and Dylan Playfair will appear in their roles of Harry and Gil, respectively, as part of Uma’s wicked pirate gang.

The special will be available on the DisneyNOW app (www.DisneyNOW.com) and Disney Channel VOD immediately following the Disney Channel premiere, which airs at 7:50 PM EDT/PDT.

Descendants and Descendants 2 were the No. 1 cable movies in 2015 and 2017, respectively. Music videos from the two movies garnered over two billion global views, and both movie soundtracks are certified gold and hit #1 on iTunes and Billboard charts. The franchise also has spawned various merchandise that has sold worldwide, including dolls and Descendants-related books, including three popular young adult novels that were featured on the New York Times Best Sellers List.

The anticipated trequel Descendants 3 premieres Summer 2019 on Disney Channel.

Watch the teaser for Under the Sea: A Descendants Story above.