As a French, I should say that this story sounds familiar to me; I speak of L'AUBERGE ROUGE, 1951, directed by Claude Autant Lara, and telling the story of a couple, owning a boarding house where they kidnap and kill people, after robbing them. Here, we are exactly in this scheme, in a very atmospheric tale, and for once, the usually annoying music that I speak so much in my comments, is pretty useful,contributing to this tense and riveting tale. But of course, you had many other films talking of this kind of scheme. MOTEL HELL, for instance, starring Rory Calhoun, though, it was more a horror comedy movie.