When a woman is found hanged from a bridge, it appears to be straightforward suicide, but Balthazar finds it strange that another victim died the same way days earlier. The fact that both victims had used a blind-dating site before their deaths points to a serial killer targeting women.

After hearing an emergency call from a distressed teenager, Bach arrives at a peculiar crime scene: an empty car with smashed windows and a trunk full of snakes. With little else to go on, Balthazar and Bach race to find the missing girl.