An elderly woman is found dead in a retirement home - apparently suffocated with a scarf. The case seems straightforward for Steffen Horndeich and Leah Gabriely from the Darmstadt homicide squad: Someone apparently had their eye on the woman's considerable cash. But then the forensic expert makes a discovery that overturns this theory. The investigators soon have to wonder whether the murder was the work of a serial killer. The case becomes even murkier when a caregiver from the retirement home is also found strangled. Horndeich and Gabriely are faced with a tangled investigation...