beginning of film: boy and girl are playing, girl locks boy in cabinet of sorts
Later: woman (aspiring actor) tries out for horror role, director asks her to scream, she kinda fails at it
At her real job, she takes home a white rat. Somehow gets taken, wakes up in this cell. Masked man feeds her, she tries to escape.
A detective comes in, gets suspicious, the man kills him.
The woman finds another woman paralyzed except for her eyes. It's the girl from the beginning of the film. The man had tracked her down, made her paralyzed with a neurotoxin, but the toxin is weakening her kidney so he found the wanna-be actress to harvest her kidney to replace hers. The woman helps the actress escape by blinking the code to the door.
Last scene: auditions for same film. Screams really well.