The opening of the movie intercuts a man and a woman being burned at the stake for witchcraft during colonial American times with a woman giving birth. That burning scene is repeated in a number of the sequels (more about them later).
Grace Churchill is the mother, a woman who emigrated from Poland with her parents, who died in a murder/suicide. She's a former junkie (if I heard correctly), but cleaned up and was surprised to find John Churchill one of the state's wealthiest men was interested in marrying her.
After the birth, they live with his mother in her huge house. Parts of the house are dusty, with things covered with sheets, and she's not supposed to go into that part. The family butler shows up to block it off when she tries to show it to her friend Linda. He becomes a little friendlier when given a fresh flower from the garden, and then isn't always there to guard the off-limits room.
That room has a mirror in it, in which she can briefly see colonial people, and also has visions of the future, though she's not sure she really saw them. She also has a dream, or maybe it isn't, in which she wanders outside at night and finds two people engaged in a ritual, and her mother-in-law Elizabeth is one of them. Blood drips out of Elizabeth's mouth.
The family also has a bunch of strange friends, older people who don't talk much. Grace's priest comes to the house to baptize William and he has a vision of flames, and becomes ill.
To some extent, as some have said, this borrows from Rosemary's Baby, which is certainly the better movie. There's even a steal of a famous shot of that movie, where the camera points through a doorway, partly showing a woman on a phone. However, the camera here actually does peer around, whereas in Polanski's film, the shot makes the viewer want to try to peer around.
Rosemary's Baby was followed by a little-seen and reportedly poor TV movie, Look What's Happened to Rosemary's Baby. Witchcraft is followed by a surprising twelve sequels so far (most of them relatively poor), though the last of them has not been released yet. Possibly the only horror series to have out-sequeled this one is the Asian anthology series Troublesome Night.
Witchcraft II picks up about eighteen years after this one, and does feature a number of flashbacks to this. Most of the sequels can stand on their own, but due to the number of flashbacks in II, it might be best to start here.
Witchcraft II also features some nudity, while there was none in this one, unless there is more than one version of the film. Some of the later Witchcraft sequels stray into erotic horror, and some feature scenes that could be considered softcore I suppose.
The main recurring character in all but two of the sequels (8 and 10) is Will Spanner, who is baby William Churchill in this one, and William Adams in the second - there's never any doubt in the movie that the baby will make it through, just what he'll be like when he gets older. Though none of them are brilliant, I don't think they're quite as bad as many others do. When in the mood for a cheap horror movie with lots of nudity, they're OK.
