What if witchcraft really existed? If our beliefs, superstitions, and legends were material? This is what Rhym, a young narcotics lieutenant, must question when she finds herself confronted with the impossible. While staking out a subway deal, a suspect magically kills his informant and drives the entire station into madness with just a handful of weed. Rhym miraculously escapes unscathed. She's unaware, but she is a witch, and that fact arouses the interest of a very particular unit of the French secret services. A group of special agents who, like the criminals they hunt, have mastered the art of sorcery...