Soon after Birgit goes missing, questions arise over a possible connection to other recent crimes — but the investigation gets off to a rocky start.

Birgit's brother, Wolfgang, grows frustrated by the lax approach to the case, particularly as it pertains to a person of interest with a criminal past.

As Wolfgang and his associates delve deeper into Kurt-Werner Wichmann's life, they discover a pattern of dark, disturbing violence that spanned decades.