Christina Pryusik is a forensic anthropologist, the chief forensic expert of the FBI in the Midwest. She is an expert in unusual murders. By studying the body of the victim, Christina can create a full-fledged profile of the killer. In fact, she is a profiler, although officially she is not one. The death of twenty-year-old Ellen McKinley became a real puzzle for forensic experts. An athletic student, a member of the university swimming team, for some reason went down into a cave with climbing equipment, swam out along the river and suddenly died on the shore from a heart attack. There were no signs of violence on the body... And soon in the neighboring state, the body of the murdered Naomi Winchester was found - in a cave among stalagmites and also without any visible damage. Moreover, it seemed as if the killer had laid it on an altar. Kristina Pryusik immediately understood: this is exactly how the previous girl should have been lying if she had not managed to escape. It seems that they are dealing with a serial killer with a strange handwriting...