Goofs

During the final séance, there is a closeup of a man's hand with a pinkie ring and gray sleeve, who is not at the table. It is a repeated shot from the previous séance, when the gray-jacketed man took part.

(at around 17 mins) The positions of Myra's hands alternate several times with changes in the point of view.

As Myra looks outwards through the rain spattered window of a child's nursery, the rain falls unnaturally onto the panes - in two bursts - as though it were sprays from a hose or watering can.

The hole in the wall between the two rooms - (the "hospital room" where the kidnapped child was being kept and the seance room) - was hidden by a framed picture in the seance room, and a few knick-knacks and bottles on a shelf in the hospital room. When Billy or Myra peeked in on the child from the seance room, they had to push the picture to the side to look through the hole. Yet when Myra was looking through the hole from the "hospital" room into the seance room when people were arriving for the seance, and she saw the child's mother, that meant the picture wasn't covering the hole in the seance room, so everyone in there would have easily seen the hole in the wall and also Myra watching them through it, but none of them did.

Myra (Kim Stanley) is supposedly a middle class English housewife (and medium), yet an American accent keeps breaking through her English accent.