We have a clergy today who no longer believe in the devil, in exorcism, in the exceptional Evil the devil can instill or even in the power that Jesus bestowed to cast out demons. —FATHER GABRIELE AMORTH

Sunday morning, May 1 of this year, was Father Amorth’s 91st birthday, but he had no plans to celebrate. He awoke just after dawn, said his usual morning prayers and one to Joseph of Cupertino, a 17th-century saint, and another to the late Father Candido Amantini, his mentor. Clutching a walking aid, he shuffled from his cell-like room to the dining room on the third floor of the Paulist Fathers residence, south of Rome’s historic center.

After his usual breakfast of caffè latte and biscotti, Father Amorth returned to his room, which had a tall window, a hospital bed, two chairs, and a wooden desk cluttered with pictures of the Virgin Mary and Padre Pio, a priest-mystic who experienced stigmata—bleeding wounds, corresponding to those inflicted on Jesus Christ on the Cross. For the next six hours, Father Amorth reviewed the mail requesting his services from around the world. Each letter contained tragic questions and appeals from people who knew Amorth only by name and reputation. He answered the letters, writing with a fountain pen, licking the envelopes and stamps himself. At two P.M., he knelt again to pray, then arose with difficulty, took up his walking aid, and made his way to an elevator, which took him to the first floor, where the small room dedicated to his work was located. The hallway was empty and dark. Whispering voices and footsteps could be heard, as from a tomb.

His old adversary was waiting.

At exactly three P.M. he began to conduct the ritual of exorcism. The possessed woman, Rosa, was in her late 30s, tall and slender, with raven-black hair. She was as dark and attractive as an Italian movie star—Sophia Loren or Silvana Mangano, with a quiet demeanor. She had a college degree but couldn’t work because of the fits and behavioral changes that came over her, most severely on the Christian holidays, such as Palm Sunday, Ash Wednesday, Easter, and Pentecost. This was her ninth exorcism with Father Amorth. As with traditional psychiatry, the patient is usually not “cured” after the first session. Father Amorth had been exorcising one man for 16 years.

Rosa arrived with her mother and father and her boyfriend, Giuliano. Her parents were in their late 50s, her father tall, white-haired, with an aristocratic bearing, her mother short, a bit plump, friendly. Giuliano was over six feet, with the build of a heavyweight boxer and short close-cropped hair. He was warm and considerate of Rosa, but I sensed a strangeness about him.

With them was Roberto (Rosa, Giuliano, and Roberto are all pseudonyms), about 50, an insurance agent in Rome. In 2012, his sister, in her 30s, was suffering from depression. One day, Roberto saw her on the floor, convulsively twisting her body and growling like a wolf. When this continued for several days Roberto took her to a psychiatrist, who was unable to help her and suggested she see Father Amorth. She required four exorcisms before she was healed.

It was Roberto who noticed Rosa at Mass, acting disturbed and disoriented the way his sister had. He brought her to Father Amorth in August of 2015.

Now, for Rosa’s ninth exorcism, Father Amorth shuffled into the small, high-ceilinged room with five burly men. Four were middle-aged priests. The fifth, Alessandro, stocky and strong with short red curly hair, was Father Amorth’s personal assistant of seven years. For this exorcism Father Amorth had granted me permission to attend and film it.