The investigation picks up when police find a fingerprint amongst Gabbai's belongings which links to the crime scene of the double murder. But who does the print belong to? Gilou is charged with conspiracy and, in an effort to get him off the hook, Laure goes out of her way to request help from the most unlikely of quarters. Nothing short of a bold move is required. Roban is determined to bring down Tarek Ziani and makes a deal with Ziani's lawyer Joséphine.

Roban can't stand to see Tarek Ziani elude his charges and tries to bring him down using the Crime Unit's investigation into a luxury vehicle racket. But Gilou's dealings with a prominent police informant threaten the outcome of the operation. Laure's team pulls out all the stops to find the little girl kidnapped by Karen's gang, as a ransom is demanded in exchange for her freedom. Will the girl be saved? And will the culprit for the double murder of Sandrine and Lucie Jaulin be brought to justice?