Pecos County Sheriff, Cody Johnson and Lieutenant, Billy Parker come across five year old, Olivia D'Angelo, an abused child in a state of Selective Mutism, wandering alone in Texas' Chihuahuan Desert. During the hunt for the man who may be responsible for her being there, Olivia's mother, Francis, who Cody later learns is a suspect in the murder of her husband, Tony, is found buried in a shallow grave halfway up the Glass Mountains. Fears of a serial killer on the loose is sparked by the discovery of the skeletal remains of a young female in the same vicinity during their search for clues. Cody focuses his investigation on the latest victim and finds himself embroiled in a tug of war with a DEA agent from the east coast. He also finds himself in a race to track down a hired assassin seen with Francis prior to her demise. Olivia, whose condition may have been brought on by witnessing the murder of her mother, is the only one who holds the key that would expose lies, greed, and long held secrets. And time becomes a big factor when an attempt is made by unscrupulous characters to kidnap her and get the information they believe may be locked in the realm of her mind. As the investigation unfolds, Cody and Susan, the new supervisor for the county's Child Protective Services, are drawn together by their mutual concern for Olivia's future welfare, her safety, and the tragic events of their own lives.