Little do they know that it is in fact a strange and mysterious 13th-century grimoire, containing an incredible power. By the time they realise what is happening to them, and how much it has already affected them, it will be too late. And when the power of the Grimoire is unleashed, the lives of these unfortunate young people will literally be turned upside down, as they will be forced to face nightmarish, increasingly dangerous situations at the limits of reason, in a crescendo of tension that will test their friendship, their physical and mental integrity, and even their very lives. All this while dark presences plot to invade and disrupt the very fabric of reality.