After discovering Julien's true identity, Fanny falls down the stairs while trying to escape him. Ready to do anything to finally reveal the truth, Fanny is convinced that finding Laura's former lover will lead them to the murderer of the two students. With Maxence's help, she hopes to trace him using the earrings he gave her... But Léonie's jealousy of Fanny suddenly takes a tragic turn...

The discovery of Patrick and Laura's affair directs suspicions towards Armelle, who could have wanted to eliminate her rival. But the latter is innocent: she spent the night of the murder in the hospital at Lucas' bedside. While the investigation is at an impasse, Fanny is faced with a realization as terrible as it is clear: what if she was the one who killed Laura? To find out, Fanny, contrary to her scientific convictions, asks her mother to prepare a drink for her so that she can finally try to recover her memory...