Nine-year-old Mathias is constantly haunted by dreams of the Silent Lady—she does him no harm, yet she appears every night, watching him with a sorrowful gaze and remaining utterly mute; now, he is terrified to fall asleep. Exhausted and desperate, his parents turn to Pietro Gerber—a Florentine hypnotist specializing in trauma therapy for children. Gerber agrees to help, only to find himself gradually drawn into a harrowing tale of persistent horror—a story the Silent Lady is determined to reveal to him. It is a story rife with unadulterated evil, murder, solitude, escape, and years of unbroken silence—a tangled web that Gerber must unravel, discovering in the process truths about himself that he had long forgotten.