It had a great beginning. The Devil's Mirror is about aging women who come across an advertisement for a beauty farm by the name of Mirror House that is supposed to restore their youthful appearance and vitality over the course of a two week stay.
When Althea can't locate her cousin Monica, she finds the advertisement in her cousin's house and it leads her to believe the woman has booked a room at the spa. Althea goes to Mirror House and instantly realizes that everything in the advertisement was a lie.
The Devil's Mirror could have been very good if it had stayed on a more normal track, but the whole devil thing got in the way, and the romance destroyed what was left of the story.
Generally speaking, insta-love is bad, but super insta-love is even worse. After less than an hour of conversation, a girl and guy are at the hand-holding stage. About 24-hours after that, they are in love, in another few hours they are planning to be married and discussing starting a family.
Perhaps I'm not romantic enough, but I don't believe anyone is in love enough after maybe 28 hours to be seriously discussing children. That is ridiculous and made me turn my nose up at the book.
Another one of these really fun 60s/70s neo-gothic novels. This one is definitely on the worse side from the Joan Aiken and Phyllis A. Whitney books I read, but it was still enjoyable.