William Castle was a master showman and this was his grandest triumph. He loved a gimmick, in this case Percepto, a device fitted beneath theater seats to enhance the climactic scenes by giving the patrons a short, sharp shock! Vincent Price, at his most maniacally deluded, is a pathologist who says he has discovered fear produces an actual physical creature that only be overcome by the release of a scream. He hopes…

There's something to be said about line delivery in horror movies when the lines aren't panicked and screaming, but understated and build tension rather than relieve it. The conceit of this plot is ludicrous, of course, but it is fifties surrealism and it has a meta concept to it, which is very weird and rewarding. The movie is quite a little gem for its genre and I highly recommend it.