In August of 1966, twenty-four-year-old Eva von Klimmer's beaten body is discovered near the French border. The note stuffed in her mouth reads "Schwarzbaden." Months later, at a ski resort in Garmisch, authorities find the body of Karla Schaeffer. The note in her mouth bears the message "Schwarzbaden." Authorities are stumped. Research has provided no information on what "Schwarzbaden" means and why the killers would deliver this cryptic message. But five living humans remember what and where Schwarzbaden had been. It had existed for less than five years in a mountainous, forested region of Germany west of Munich. The location had been selected by Adolf Hitler in the 1930s and became the most inhumane of the Nazi concentration camps. Now, more than twenty years later, the doctors who worked at Schwarzbaden are forced to remember the atrocities performed there. Dr. Frederick Zwick has lived in fear that the real story of this secret facility would become known, but in the past twenty years he's tried to atone for the evil in which he participated. As the children of the other doctors who worked at Schwarzbaden are murdered, Zwick hopes there is time to save his family from the same fate.