What is the title of a trilogy of three women called to a dark castle and tasked to free the couple in there?

The women have romances and battle demons, I think there are rings involved: a terrific read.What is the title of a trilogy of three women called to a dark castle and tasked to free the couple in there?
You should have gotten an answer to this. Try literature instead.





This question does not belong in Mythology and Folklore. You probably won't get a good answer until you get the question rerouted.

trojan