The Hunger Games: Mockingjay has cast its first newcomer: Game of Thrones star Natalie Dormer.

Lionsgate made the announcement in a press release this afternoon. The character Cressida is a resident director in the Capitol who joins the rebellion and flees to District 13. Cressida is asked by Plutarch Heavensbee (played by Philip Seymour Hoffman) to film Katniss during the rebellion so they can encourage fellow rebels to unite.

Before Mockingjay, she can be seen in Ron Howard’s Rush, Ridley Scott’s The Counselor, and the indie film Posh. She plays Margaery Tyrell on HBO’s Game of Thrones, which is based on the A Song of Ice and Fire series by George R.R. Martin.

The Hunger Games: Mockingjay Part 1 opens in theaters November 21, 2014 and Mockingjay Part 2 opens November 20, 2015.

In June we told you that Julianne Moore is up for the role of President Coin, but no word about her signing on to the role has been reported since then.

Mockingjay is the third and final book in Suzanne Collins’ The Hunger Games trilogy. Lionsgate decided to split the last book into two parts; a move popular with book-to-film adaptations in recent years like Harry Potter, Twilight, and The Hobbit.

Meanwhile, Catching Fire hits theaters on November 22 of this year.