Letters, loneliness and a deadly pact: With Olivier in custody, psychologists analyze her history with Fourniret to understand her role in his crimes.

June, 2003. Belgian authorities arrest Michel Fourniret for attempted kidnapping and assault. Linking him to two other cases, they interrogate his wife.

A prosecutor recalls Olivier and Fourniret's sheer lack of empathy as they uncovered bodies. Later, their ownership of a château is called into question.

Olivier is taken out of her cell to help with a cold case in 2021, but her motives are unclear. After Fourniret's death, can she recover her humanity?

When the trial opens, Olivier's role as a mother spikes public fascination — and hatred. As the couple's crimes come to light, so does their sex life.