Alexandra Meshcheryakova works as a cleaner in the department of the investigative committee of her native Kalinov. She tries to forget her past life, where she dealt not with shoe marks on the floor, but with traces of crimes. Sasha was a profiler and helped catch several serial killers, but after a tragic accident she decided to break with the profession. Now, wiping the dust, she is forced to listen to the versions of investigators puzzling over a series of brutal murders. It's getting harder to keep quiet, because she sees that they're going the wrong way.