With Eddie Redmayne set as the male lead for J.K. Rowling’s Harry Potter spinoff “Fantastic Beasts and Where to Find Them,” Warner Bros. is firming up the rest of the film’s cast.

“Inherent Vice” actress Katherine Waterston has landed one of the female leads opposite Redmayne in the first installment of the new franchise, which is being planned as a trilogy.

Waterston will play the pivotal role of Tina, short for Porpentina, a witch who — unlike the beloved characters from Rowling’s Harry Potter books — works her magic in the U.S. She meets magizoologist Newt Scamander (Redmayne) when he stops in New York City on his travels to find and document magical creatures.

Two pivotal roles in the film have yet to be cast: Queenie, Tina’s younger sister, and Jacob, a rival of Scamander’s.

The studio is said to be looking for more established faces for the spinoff, unlike the newcomers they discovered for the original “Harry Potter” franchise.

David Yates is directing with Rowling making her screenwriting debut on the trilogy.

Set in New York roughly seven decades before Harry Potter’s saga starts, “Fantastic Beasts” is based on the Hogwarts textbook of the same name and follows the adventures of its author, Newt Scamander. Scamander is described as a “magiczoologist,” which in the “Harry Potter” realm is a person who studies magical creatures. Besides Scamander, there are four other main roles — two American girls and two American boys — that the studio is looking to cast.

“Although it will be set in the worldwide community of witches and wizards where I was so happy for 17 years, ‘Fantastic Beasts and Where to Find Them’ is neither a prequel nor a sequel to the ‘Harry Potter’ series but an extension of the wizarding world,” Rowling explained.

The film is set to bow on Nov. 18, 2016.

Waterston is repped by UTA and Silver Lining Entertainment and can be seen next in Universal’s biopic “Jobs.”