Parisian detective Lise meets her childhood sweetheart Antoine by chance. Extremely happy about the reunion, the two arrange to meet. But Lise's duties as an inspector thwart their plans.

Inspector Lise Tanquerelle is under stress, as she often is, and is speeding through the streets of Paris when a cyclist suddenly comes towards her. Lise brakes too late and knocks the man down. As luck would have it, the cyclist is her childhood sweetheart Antoine Lemercier. Single mum Lise and the single professor of Greek history arrange to meet that very evening. But the rendezvous is short-lived, as the detective is called to a crime scene. A member of the National Assembly has been stabbed to death in cold blood and Lise is asked to take on the case. Lise, who is passionate about her job, tries to reconcile everything: Her child, Antoine and the murder case. But her next meetings with the professor are also interrupted by phone calls from police colleagues. She tries to keep her profession a secret from Antoine, who, like many of his academic friends, hates the authorities. The unsolved murder develops into a series of murders. Two other deputies are executed in the same way. But there is no trace of the perpetrator. Inspector Lise, who is taken off the case due to a lack of results, finds something in common between the three victims: They all have the same lover. Does this lead to the murderer?—Arte

Romance in the prime of life. When Lise's car bumps Antoine's bike, they recognize each other from a brief fling 20 years before while at the Sorbonne. He's now a professor of Greek; she's loathe to tell him she's a police inspector. A call interrupts their first dinner date: a Deputy of the National Assembly has been murdered. She has a suspect, another Deputy, and must track him while deflecting Antoine's eye from her vocation. All roads in the inquiry lead to Christine Vallier, the dead Deputy's mistress, a beguiling 22-year-old whose mother ran the Assembly's snack bar. When more deputies die and Antoine learns Lise's identity, she must act quickly solve the crime and save her future.—<[email protected]>