Marvel’s Jessica Jones is adding a major (and mysterious) role in season 2.

Two-time Oscar nominee and Golden Globe winner Janet McTeer (The White Queen, The Woman in Black, Damages) is joining the cast of the acclaimed Netflix hit, EW has learned exclusively. The British actress will play an “undisclosed character who will have an enormous impact on Jessica’s life.” The casting represents the first major addition to Jessica Jones for the new season.

“We are so fortunate to have an actress of Janet’s talent and stature join what is already an incredible cast,” said Marvel TV chief Jeph Loeb. “Our second season of Marvel’s Jessica Jones aims to capture what audiences loved about our first, and Janet will be key to achieving that goal.”

Added series creator Melissa Rosenberg: “We couldn’t possibly be more excited to work with Ms. McTeer for our second season. Her gravitas and authenticity are the perfect ingredients for all we’re trying to create this year. She disappears into roles, gives her characters extraordinary dimension and depth. We’re incredibly fortunate to be able to collaborate with her.”

“Janet McTeer is the consummate actor, slipping seamlessly into each character she brings to life,” added Cindy Holland, vp of content at Netflix. “We’re thrilled to have her join the outstanding cast, led by the fearless Krysten Ritter.”

Let the speculation begin on who McTeer will play!

Jessica Jones will once again have 13 episodes in season 2. The show stars Krysten Ritter as the title character and featured Carrie-Anne Moss, Rachael Taylor, Luke Cage lead Mike Colter, and David Tennant during its first season back in 2015. Rosenberg has noted she plans to hire all-female directors for the new season. No premiere date is set, though next year looks likely. Before then, we’ll see Jones in the eight-episode miniseries The Defenders which is coming Aug. 18.