A police chemist, Aurélie has been raising her son alone since the death of her partner. When Commissioner Max Vernet uses her skills to investigate UBH, a new synthetic drug that is starting to claim victims, she has no idea that she will find herself infiltrated into the heart of a network of young and dangerous traffickers. Faced with the charismatic Jesus, who runs the network from Marseille, does she have a chance of successfully completing her mission? To save her son, Aurélie no longer has a choice. Maternal love is a hard drug...