The lonely bleakness of a lighthouse on an island off the coast of Scotland is the perfect setting for the equally bleak “The Vanishing” (2019). The keepers of the light – through no fault of their own – suddenly have a secret to keep as well. Things rapidly degenerate from there, in a Hitchcock-like descent into violence and paranoia, unfolding like so many other movies where a handful of people are trapped somewhere. But there’s something missing. It’s like a slasher movie without a slasher. Things seem to be building toward something, but we never get there. It’s us who are trapped.