Newly retired Chief Inspector Kovak returns to the small northern German village where a horrific crime took place 20 years ago.
A little girl was brutally murdered, and her killer was never caught. Kovak is convinced of the murderer's identity. He wants to redeem the promise he made to the girl's parents all those years ago: to bring the killer to justice.
One of the suspects was Michael Adam, a renowned physics professor at the University of Greifswald. But because there was insufficient evidence, the homicide squad, overseen by young state police official Ella Schönemann, had to drop the case against Adam.
Upon his return to the village, Kovak begins systematically monitoring the actions of Adam and his girlfriend Luisa. Soon, bitter adversaries Kovak and Adam are face to face. Where does the truth lie? When can something be deemed proven, and when is it just a suspicion?
