Murder at Hollow Crest

The book is basically about a woman who was raised on the island with her father. Due to his job, he was not able to spend much time with her. She had befriended a classmate and stayed with the classmate's family most of the year. The two girls grew up together, went to college together, and were only separated when Helen married and moved to New York. After twenty years, Helen returns to the San Juans to visit her friend and becomes involved in a murder mystery. She and her friend, Susan, spend countless hours trying to solve the murders. Can they do it? Will they do it?