Netflix is teasing the new film Damsel.
Damsel is written by Dan Mazeau and directed by Juan Carlos Fresnadillo (28 Weeks Later).
Brown plays a princess "who agrees to marry a handsome prince -- only to discover it was all trap: The royal family recruited her as a sacrifice to repay an ancient debt."
"She's then thrown into a cave with a fire-breathing dragon, relying solely on her wits and will to survive," an official description reads.
The poster shows Brown's character standing in the crevice of a steep wall of the cave."This is NOT a fairytale," the tagline reads.
Angela Bassett, Robin Wright, Ray Winstone and Nick Robinson also star.
Brown is best known for playing Eleven on the Netflix series Stranger Things, which will return for a fifth and final season.
Netflix celebrated Stranger Things Day on Monday and gave a behind-the-scenes look at the play Stranger Things: The First Shadow.
