Balthazar relies on drugs to numb the pain when Lise's killer sends him a video of her being murdered; a disturbed man wearing a woman's bloody scalp walks into the police station.

After receiving a threat from Lise's killer, Balthazar worries his new girlfriend, Maya, is in danger; Bach is called to investigate a body found in a pond, but the case turns personal when she realizes the victim is someone close to her.

Balthazar and Bach finally track down a suspect in Lise's murder case, only to find he has been dead for 10 years and the real killer has been using the identity of the deceased; teenagers are butchered during a camping trip.

Balthazar examines a dead woman who was shot and buried alive, and finds a USB drive hidden in her wounds that reveals portraits of seven missing people, including her son.

After hearing an emergency call from a distressed teenager, Bach arrives at a crime scene with an empty car with smashed windows and a trunk full of snakes.

Balthazar locks himself inside a derelict toy store after he examines a body and determines that the victim died from an accelerated version of the bubonic plague.

When a woman is found hanging from a bridge, it appears to be straightforward suicide, but Balthazar finds it strange that another victim died the same way days earlier after using a blind-dating site.

Balthazar and Bach travel to a remote mountain village when a husband and wife suffer a knife attack that bears the marks of a serial killer who is supposedly in prison.

Balthazar analyzes bones discovered in an old building and finds three bodies dating back to the Middle Ages, and one recent victim partially dissolved in acid.

When a dead dog covered in human blood leads police on a frantic hunt for a missing infant, suspicion immediately falls on the child's nanny, who is not who she says she is.

Balthazar arrives on the scene of a horrific car accident and finds the body of a woman a few yards away, but he determines she died several hours earlier and her corpse was in one of the car trunks.

Balthazar examines a dismembered corpse found in the river, but when the body parts don't match up, he realizes there's another victim.

While at the movie theater, Balthazar is called to help a woman who appears to have been stabbed, but after realizing the blood she's covered in belongs to someone else, he races to find the other injured person.

Bach calls on Balthazar to examine a young woman found dead in a truck, but the deceased's body is completely frozen and a piece of evidence connects her to a seemingly unrelated case.

Reeling from the realization that the person who murdered his wife could still be at large, Balthazar arrives at the gruesome scene of a beaten man with his face torn off.

When called to a crime scene, unconventional forensic pathologist Raphaël Balthazar clashes with the new, no-nonsense chief inspector, Hélène Bach, but they must work together to solve the double homicide of a public prosecutor and his wife.