The third “Descendants” book titled “Rise of the Isle of the Lost” penned by Melissa de la Cruz is set to be released on May 23 prior to the “Descendants 2” movie premiere on July 21. The new book from Disney Publishing features Ursula’s daughter Uma as a lead character; she is joined by other new characters, particularly the children of other Disney villains, such as Captain Hook’s son, Harry, and Gaston’s son, Gil.

The “Rise of the Isle of the Lost” is supposedly a prequel to the “Descendants 2” movie. This latest book from the novel series features Mal and Uma battle it out as they search for King Triton’s trident, known as a magical object that will enable Uma to run free from the Isle of the Lost. Joining Uma as her pirate crew members are Harry and Gil. The complete first chapter of the new “Descendants” prequel book has been made available by Disney.

Meanwhile, the “Descendants 2” will feature Mal, played by Dove Cameron, who will come face to face against Uma, the daughter of “The Little Mermaid” villain Ursula. The upcoming sequel to the hit original Disney Channel film, “Descendants,” will highlight the adventures of the children of Disney’s popular villains. These include Maleficent’s daughter Mal, Cruella de Vil’s son Carlos, the Evil Queen’s daughter Evie, and Jafar’s son Jay. They will attempt to infiltrate into the peaceful kingdom of Auradon where many heroes reside, as reported by Entertainment Weekly.

Uma, Gil, and Harry will be the lead terrorizing trio in “Descendants 2.” They are all deeply bitter about not being chosen as students in the splendid Auradon Prep. China Anne McClain will play Uma, Thomas Doherty will take on the role of Harry, and Dylan Playfair will play Gil. Original cast members from the first “Descendants” movie- Dove Cameron, Cameron Boyce, Sofia Carson, Booboo Stewart, and Mitchell Hope- are all set to return and reprise their roles. “Descendants 2” is helmed by Kenny Ortega, who previously directed the first film.

“The Isle of the Lost is an island that houses the most infamous villains, so it seemed natural for a pirate gang including the offspring of Ursula, Captain Hook and Gaston to emerge as we take audiences deeper into the “Descendants” world,” Ortega said in an interview with Entertainment Weekly. “As our rich story unfolds, Uma, the daughter of the sea witch Ursula, proves that she’s a force to be reckoned with as the leader of a pirate gang and the new self-proclaimed queen of the Isle.”

Ortega touched on Uma’s pirate gang and referred to her allies as “devoted hunchmen.”

“…Harry, Captain Hook’s son, her right-hand man who is always ready for action, and the handsome yet thick-headed Gil, Gaston’s son,” he added.

"Descendants 2" recently finished production for an official premiere on July 21, Friday, at 8 p.m. ET on Disney Channel as well as on Disney XD, ABC, Lifetime, and Freeform. The “Rise of the Isle of the Lost” will be made available for sale beginning May 23, Tuesday.