When a corpse is found in the Seine, police inspector Antoine Jouin starts his first murder investigation.

Meg begins spying for Puybaraud and infiltrates the Guerin family.

Jeanne agrees to help Jouin with the case.

Pressure mounts on the police; Meg's game becomes increasingly dangerous.

Meg has fallen for intelligence officer Gabriel Sabran, but evidence mounts against him in the Berger case.

Fiersi breaks with the superintendent and gives Jouin a crucial piece of information.

Lepine receives unexpected help from the anarchists; Jouin uncovers the true motives for the crime.

Meg plays her last card; Jouin learns justice isn't always served.