Face23, a smartphone app that uses facial recognition to identify people and compiles all the information available online about them, is causing quite a stir in Bielefeld. Wilsberg, who is not at all a fan of technology, is unfazed at first. But when a video is posted online showing Alex Holtkamp kneeling next to a dead man, Wilsberg is forced to take a closer look at the app. Alex becomes a suspect in the murder.