While the original script, something called "The Devil's Doorway," showed promise, various re-writes and compromises have resulted in a movie which makes so little sense that it's best viewed as an "in-flight" movie. One of those things you halfway watch while doing something else.
The movie begins with a basic implausibility. Interior decorator Katherine Ross is lured from L.A. to England by a lucrative but mysterious job offer. She and boyfriend Sam Elliott decide to fly over a few days early to see some of the English countryside. They're involved in a minor motor accident on a rustic lane and are taken by the other driver to his nearby home to await repair of their vehicle. What do you know, this home just happens to be the very place where Katherine Ross was intended to go all along!
Therein follows some murky activities involving other guests at the home who seem to be part of a Black Magic cult. Gruesome death follows gruesome death culminating in an ending which doesn't really resolve questions raised by the preceding plot.
On the plus side, the two leads are attractive sorts and they're surrounded by a competent British cast which gives a better effort than circumstances warrant. What's more, the large countryhouse in which the action occurs provides just the right atmosphere.
One curious note. While Katherine Ross is warmly dressed throughout with turtleneck sweaters and long skirts, co-star Sam Elliott gets to strip for a rather-extended shower scene. As he crosses the bathroom toward the shower, the camera lingers on the back of his naked body, even though this part of the scene serves no plot purpose whatsoever.
Fortunately Elliott, at about age 33, has the necessary buns-by-Michelangelo to make this moment more of a highlight than an embarrassment.