The “Percy Jackson and the Olympians” series at Disney+ has found its Grover Underwood and Annabeth Chase.

Variety has learned exclusively that Aryan Simhadri will star as Grover with Leah Sava Jeffries set to play Annabeth. They join previously announced series lead Walker Scobell, who will play Percy.

The series adaptation of the Rick Riordan book series was ordered at the streamer back in January. The live-action show tells the fantastical tale of the titular 12-year-old modern demigod (Scobell), who’s just coming to terms with his newfound supernatural powers when the sky god Zeus accuses him of stealing his master lightning bolt. With help from his friends Grover and Annabeth, Percy must embark on an adventure of a lifetime to find it and restore order to Olympus.

Grover is a satyr, half boy and half goat, disguised as a 12 year old boy. He cares deeply about others and will always choose what is best for them, sometimes at his own expense. Though cautious by nature, he’ll always throw himself into a fight to protect his friends, especially his best friend Percy.

Annabeth is a true daughter of the Greek goddess, Athena. She is a brilliant strategist with an active and curious mind. After having spent the last five years at Camp Half-Blood, she longs to test her mettle in the human world, of which she barely remembers. She trains Percy to survive the mythological world, and in turn, he helps her connect with her humanity.

Simhadri most recently appeared in the Disney+ remake of “Cheaper by the Dozen” and starred in the Disney Channel original movie “Spin.” He also starred in the Disney Channel improvisational sitcom “Just Roll With It” and the Disney Junior animated series “Mira, Royal Detective.” His other credits include the Paramount+ animated series “Adventures in Wonder Park,” “The Spongebob Movie: Sponge On The Run,” the “Adventure Time” TV movie “Distant Lands,” and the WWE/Netflix movie “The Main Event.”

He is repped by Paradigm, Industry Entertainment, and Goodman Genow

Jeffries is known for her role as Lola in the Fox music drama “Empire” as well as for playing Lil Rel Howery’s daughter, Erica, in the Fox multi-cam comedy “Rel.” She also starred in the Lifetime movie “Faith Under Fire.” Up next, she will be seen opposite Idris Elba in the thriller feature “Beast” and in the Amazon feature “Something From Tiffany’s” produced by Hello Sunshine.

She is repped by The Osbrink Agency, M88 and Fox Rothschild.

Production on “Percy Jackson and the Olympians” will begin soon in Vancouver. Riordan and Jon Steinberg are writing the pilot with James Bobin directing. Steinberg and his producing partner Dan Shotz are overseeing the series and serve as executive producers alongside Bobin, Rick Riordan, Rebecca Riordan, Bert Salke, Monica Owusu-Breen, Jim Rowe, Anders Engström, Jet Wilkinson, and Gotham Group’s Ellen Goldsmith-Vein, Jeremy Bell, and D.J. Goldberg. 20th Television is the studio. Salke was formerly the president of Touchstone Television and originally put the show into development. It is scheduled to begin production this summer.

(Pictured, from left to right: Leah Sava Jeffries, Walker Scobell, Aryan Simhadri)