"You remember how Alice wasn't always in Wonderland? Alright, well, I wasn't always in Room. I'm like Alice."

Brie Larson is trying to verbally describe freedom with limited success to her 5-year-old son and fellow captive in the teaser trailer for Room.

"You remember how Alice wasn't always in Wonderland? Alright, well, I wasn't always in Room. I'm like Alice," she tells Jack while inside their windowless, 10-by-10-foot space, before brainstorming a potential escape plan. "You're gonna love it — the world."

Lenny Abrahamson directs A24's adaptation of Emma Donoghue's best-selling novel. Jacob Tremblay, Joan Allen and William H. Macy also star in the film, which will screen in September at the Toronto Film Festival.

Donoghue's novel is told from 5-year-old Jack's perspective. He and his "Ma" live in a small, windowless room, where they are held captive by a man. Ma has done everything she can to create a complete and fulfilling life for her son, but things eventually reach a breaking point and she hatches a risky plan for escape.

Room opens on Oct. 16 in a limited bow, before expanding nationwide on Nov. 6.

Watch the video below.