Willi Geismeier thought he'd faced the worst of humanity on the battlefield in World War I, but when he returns to Munich he is drawn into an investigation that proves to be just as chilling.

1913, Munich. Nineteen-year-old Willi Geismeier is showing great promise as a rookie detective in the Munich police department when he is sent to fight in World War I. After narrowly surviving the horrors of the conflict, Willi returns home, where the challenges he faces seem just as grave.

The Spanish flu or 'Grippe' rips through Munich with devastating consequences and Willi, now back in the police force, finds himself investigating an insurance scam, missing drugs and the mysterious death of a prisoner. As chilling links emerge between all three, Willi confronts a grotesque scientific theory and a dangerous ideology taking root in society that could lead him to a killer, but there are those who are just as determined to stop him in his tracks . . .