The penultimate story in Waiting in the Shadows is close to mainstream horror, with overtones of classic Gothic tales.
Patsy has had a nervous breakdown thanks to marital problems. When she is released from hospital her husband takes her to their new home, a large Victorian affair that she does not like. Just to make things a bit worse, hubby also installs a housekeeper-cum-warder to watch over Patsy. There are shades of 'The Yellow Wallpaper' in this setup, but things work out rather differently.
One room in the house is a bit weird. A large mirror conceals a door, and behind it lurk inhuman creatures seeking a way into our world. Patsy's misery and confusion serves as their admission. At first it seems as if the creatures are Patsy's ally, but things are not quite so clear-cut.
A tale that could have formed one of the darker episodes of The Twilight Zone, here, and all the better for it. Next time I'll round off this review. Are there still copies of this book to be had? Check out the link above and see.