Oscar Isaac is rounding out the cast of Zack Snyder’s “Sucker Punch.”

The Warner Bros./Legendary drama, centering on a girl who’s institutionalized by her stepfather and retreats into an alternative reality, will begin shooting this fall. Emily Browning plays the girl; Carla Gugino, Vanessa Hudgens, Jamie Chung, Jena Malone, Scott Glenn and Abbie Cornish are also on board.

Zack and Deborah Snyder are producing “Sucker Punch” through their Cruel & Unusual banner. He’s directing from a script he co-wrote with Steven Shibuya.

Isaac, last seen in “Body of Lies” and “Che,” has been in production on Ridley Scott’s untitled Robin Hood adventure for Universal alongside Russell Crowe, Cate Blanchett, and William Hurt. He’ll be seen next in Alejandro Amenabar’s romancer “Agora,” with Rachel Weisz, and in indie drama “Balibo,” set amid the Indonesian invasion of East Timor in 1975.

He’s repped by WME and Inspire Entertainment.