Yann, an athletic young man, was murdered in the middle of the night in the Bois de Boulogne. He was a "survivalist", he trained himself to survive in the event of a societal collapse, without electricity, petrol, money, or food... But Alice and Marquand make a discovery that changes everything: until he came of age, Yann grew up isolated from the world, in the middle of nature, after being kidnapped by his father during a divorce gone wrong... To this day, the father has still not been found. Alice's father finds a picture of Chahine with another woman. He decides to confide in Victor.
