The church smelled of old incense and candle wax. Dust motes painted red and yellow and blue by light filtering through stained-glass windows stirred into eddies and whorls as the priest raised his arms over the bottles of water on the table in front of him.

"Deus, qui ad salutem humani generis maxima quæque sacramenta in aquarum substantia condidisti... " he intoned. "God, who for the salvation of the human race has built your greatest mysteries upon this substance, in your kindness hear our prayers and pour down the power of your blessing into this element, prepared by many purifications. May this your creation be a vessel of divine grace to dispel demons and sicknesses, so that everything that it is sprinkled on in the homes and buildings of the faithful will be rid of all unclean and harmful things. Let no pestilent spirit, no corrupting atmosphere, remain in those places: may all the schemes of the hidden enemy be dispelled. Let whatever might trouble the safety and peace of those who live here be put to flight by this water, so that health, gotten by calling Your holy name, may be made secure against all attacks. Through the Lord, amen."

Mary Teresa started awake, the memory of her dream flooding full force into her mind. A touch between her legs only confirmed what she already knew: the hair was wet and matted, and her thighs were slick. The devils had visited and she had sinned in the night. Again.

She rolled out of bed and knelt before the small shrine at its side. With her hands reverently clasped, she gazed at the statues of Jesus, the Virgin Mary, and St. Teresa of Ávila; a long-dried palm frond; a bottle of holy water and small glass; six votive candles. "Forgive me, Father, for I have sinned," she whispered. "Punish me, cleanse me, remove sin from my heart.

"Ave Maria," she continued, her whisper fading, her lips moving silently around the words.

She poured a bit of the holy water into the glass, and drank. Then she crossed herself, rose, and went to the shower.

Mary Teresa had a terrible time keeping her mind on her work. Her regular customers noticed, as they passed her deposit slips and checks and counted their withdrawals, and they said, "You don't seem yourself today, Mary Teresa. Is everything all right?"

The devils had been gone with her waking, but their whispers, in the voices of Jimmy and Patrick and Conor, tickled at her mind as traces of their spectral fingers left tingles on her breasts and her thighs.

When she was sixteen, she dreamed of love and marriage and children, of a bright house filled with the sounds and joy of living. After a movie one Saturday night, she and Jimmy had been cuddled together in his father's car before he walked her to her door. He whispered warm puffs of breath in her ear as a finger followed the contours of her forehead and cheek and lips.

"You are so beautiful, Mary Teresa," he said. "I love you."

Mary Teresa turned into his kiss, finding his lips surprisingly soft and welcome, and accepted the touch of his tongue without question. But where she had expected to find warmth, she encountered a heat that melted her bones and molded her body to Jimmy's. When his hand crept up her side and closed on her breast, the heat turned to fire, and she knew--she knew--even with out knowing how or why, that this was the sin the nuns had warned her about. With a start, she pushed Jimmy away. "No!" she gasped.

That night, the devils visited her for the first time, immune to her cries of No! and her attempts to push them away. Relentlessly, they told her in Jimmy's voice how beautiful she was and how much they loved her. They touched her bare skin, pinched at her nipples, and kissed at her thighs until the fire in her body was unbearable. In the morning, she awoke with a wetness between her legs and fear in her soul.

She could barely wait to get to confession. "Forgive me, Father, for I have sinned. Punish me, cleanse me, remove sin from my heart."

"Would you mind counting that again, please, Mary Teresa?"

By the end of the day, Mary Teresa was exhausted, and the walk back to her apartment felt as if she were climbing a mountain, dragging one weary foot after the other. It took every ounce of energy she had left to prepare a simple dinner of fish, bread, cheese, and a salad.

When she was twenty-six, Patrick had slipped past her guard and into her heart. No longer sixteen, she welcomed the heat that made her flow into his embrace, and she did not resist his touch. As his palm slid up her ribcage, hers moved downward across the hard planes of his chest and stomach. When his hand closed over her breast, her hand closed over hard sin, and courage abandoned her. "No!" she screamed, pushing Patrick away.

And that night, the devils returned, laughing as they ignored her fear and her screams, forcing her to feel in her sleep what she was unable to permit herself in waking. In Patrick's voice they taunted again and again, making her flesh fevered, her hand full, and her loins painfully empty. In the morning, she awoke gasping and terrified--and wet.

Sister Teresa shivered as she sat at the desk of her rude cell in the Carmelite convent at Ávila one quiet winter night in 1581. A tallow candle sputtered smoky yellow light as her pen scratched out her thoughts. "From long experience I have learned," she wrote, "that there is nothing like holy water to put devils to flight and prevent them from coming back again. They also flee from the cross, but return; so holy water must have great value. For my own part, whenever I take it, my soul feels a particular and most notable consolation. In fact, it is quite usual for me to be conscious of a refreshment which I cannot possibly describe, resembling an inward joy which comforts my whole soul."