A frustratingly not-terrible action thriller.
Anthony Waller's "Mute Witness" is one of those films, like "Halloween" or "Blood Simple," where a strong story and a skillful use of horror film technique causes you to forget the low budget and limited production values.
The movie takes place mostly within a Moscow film studio and in a few shabby apartments and on dark night streets. Yet it grabs you and - apart from a few fake scares recycled out of countless other movies - wins your respect.
The movie's heroine is Billy (Marina Sudina), a young mute who is working as the makeup and special effects person on a low-budget horror film. One night, lingering behind to finish a task, she is mistakenly locked inside the studio and cannot, of course, call out for help. She tries telephoning her sister's apartment and tapping on the receiver, but the sister's husband dismisses the calls as pranks. It appears she will have to spend the night.
Wandering back to the set, she is startled to find it being used for other purposes. Some of the technicians on the horror film are using the company's facilities for their own after-hours production. Billy, hidden behind scenery, watches. It appears they are making a porno film. Then, with horror, Billy realizes they are making a snuff film: She witnesses the gruesome death of an actress.