Nancy Drew; A sweet, kind, intelligent and curious young lady of 18 years who loves solving mysteries with her friends and family. Nancy is as clever and sly as a fox. She loves solving riddles and mysteries with her friends and family. Nancy Drew lives with both her wise and respectful father (Carson Drew) and her sweet and caring housekeeper (Hannah Gruen). Nancy loves to help her dad with his criminal cases and she has developed her own journey solving cases that her close ones need help with. This is actually the 6th mystery Nancy has become involved with. She would usually explore in, around and out of town to get to the bottom of each thickening plot which lies underneath the truth. In this engaging mystery, Nancy Drew spends a week at Shadow Ranch with her friends; Bess Marvin and George Fayne. But things quite quickly turn into a mystery that she and her friends need to solve. This trio soon learns and investigates a strange clan of people who are living and working in a cave close by. Nancy and her accomplices need to uncover the cave people's ulterior motives and find out what is going on behind those walls. This story is very interesting and unexpected with twists and turns along the way. Not only does Nancy have to use her critical thinking, but she also has to rely on her friends to aid her along the way. I absolutely loved this book because it was so absorbing and fascinating to read. I also loved how the setting and events consistently changed to keep the reader interested. I would recommend this book to anyone of any age who loves reading about riddles, puzzles and mysteries!