After the death of his son's babysitter caused by UBH, a synthetic drug that is beginning to flood the market, Commissioner Max Vernet convinces his superiors to mount an undercover operation, the only way to trace a production and distribution network that is as mysterious as it is dangerous. He forces Aurélie, a single mother and police chemist, to offer her services to the network run from Marseille by the charismatic Jesus, under the pretext of being able to improve the product...