An epidemic looms. Anne-Marie Leclerc, director of the Emergency Public Health Laboratory, must deal with an outbreak, an overzealous cabinet minister, and a media storm. To top it off, she discovers that her husband has been deceiving her. All this is trivial compared to what’s in store...

Nelli tells Anne-Marie that a strange illness is affecting people she’s close to. Anne-Marie initiates an investigation into the deaths of the two homeless people. The young girl infected by Nelli’s cousin risks infecting others. In the lab, the arrival of a new staffer affects Anne-Marie’s work.

The dead can’t talk. Anne-Marie needs to know if people close to the victims are suffering from the disease. The clock is ticking. The lab team does all it can to break the chain of transmission and discover the nature of the virus.