The Spiral StaircaseGoofs

As the projectionist hand cranks the projector which is on a shaky tripod, the projector wobbles noticeably, but the image on the screen is steady.

After Blanche has her argument with Steven, she goes into Helen's room to talk to her. Whilst Helen is packing her suitcase, she takes a picture frame off the nightstand and lays it on the bed twice.

After Helen first fetches the ether from the bathroom cabinet, she leaves the bathroom without closing the cabinet door. No one goes back to do anything with it, and seconds later the cabinet door has closed itself.

When Helen first walks up the main staircase, she pauses to look at herself in the mirror. In the next shot as the camera slowly rolls backwards, she is still looking in the "mirror", but there is no reflection of herself (just a painting designed to look like mirror).

SPOILER:Mrs. Warren is presented as bedridden yet, when Helen is searching for the gun she checks the entire room - though this may suggest that she already knows her employer is not such an invalid as she makes out.

The silent film showing at the Village Hotel is extremely scratched and flickery. This is as the print would be in 1945, but at the time the film is set it should be rather cleaner and less damaged.

Shadow of camera can be seen on the wall of Blanche's bedroom when she goes to talk to Helen.