The Deadly Crescent — Marcia Miller

Pamela Burke and Vicky Dale had been best friends your years. When Pam's Aunt Mamie, who lived in the same town as Vicky phoned Pam to say that Vicky was behaving strangely and seemed to be in deep trouble, Pam immediately said good-bye to her boyfriend, Hank Murrow, and taking her huge Great Dane, Digger, sped off to Daleton, in Northern California.

Mysterious events started to happen soon after Pam's arrival. She was unable to reach Vicky, and then one day she saw her on the street and was actually snubbed by her. Then Pam learned that a man named Ernst Jarvos -- a doctor -- had moved into Vicky's home with his wife and son and seemed to exert a strange and powerful control over her friend. Who was Dr. Jarvos and why did Vicky appear to depend on him so much? And who, not long afterward, attempted to break into Pam's room one night -- and why would anyone try to poison Digger?

Vicky's mountain lodge, Shifting Shadows, where Pam has followed her friend, becomes the setting in which both Pam and Vicky find themselves in a terror-filled situation -- and it is here, too, that the grisly series of nightmarish events come to a tragic conclusion.