Prologue

      South Boston, Massachusetts

      2:00 p.m., EDT

      July 12, Thirty Years Ago

      A scrap of yellow crime scene tape bobbed in the rising tide of Boston Harbor where the brutalized body of nineteen-year-old Deirdre McCarthy had washed ashore. Bob O’Reilly couldn’t take his eyes off it.

      Neither could Patsy McCarthy, Deirdre’s mother, who stood next to him in the hot summer sun. Coming out here was her idea. Bob didn’t want to, but he didn’t know what else to do. He couldn’t let her go alone.

      “Deirdre was an angel.”

      “She was, Mrs. McCarthy. Deirdre was the best.”

      Ninety degrees outside, and Patsy shivered in her pastel blue polyester sweater. She’d lost weight in the three weeks since Deirdre hadn’t come home after her shift as a nurse’s aide. At first the police had believed she was just another South Boston girl who’d gone wrong. Patsy kept at them. Not Deirdre.

      She disappeared on the night of the summer solstice. The longest day of the year.

      Appropriate, somehow, Bob thought.

      Patsy’s eyes, as clear and as blue as the afternoon sky, lifted to the horizon, as if she were trying to see the island of her birth, as if Ireland could bring her the comfort and strength she needed to get through her ordeal. She’d left the southwest Irish coast forty years ago at the age of nine and hadn’t been back since. She loved to tell stories about her Irish childhood, how she was born in a one-room cottage with no plumbing, no central heat—not even an outhouse—and how she’d learned to bake her famous brown bread on an open fire.

      Bob wondered how she’d tell this story. The story of her daughter’s kidnapping, rape, torture and murder.

      The police hadn’t released details, but Bob, the son of a Boston cop, had heard rumors of unspeakable acts of violence and depravity. He was twenty and planned on becoming a detective, and one day he would have to wade through such details himself. He hoped the victim would never be someone he knew. He and Deirdre had learned to roller-skate together, had given each other their first kiss, just to see what it was like.

      “I heard the cry of a banshee all last night,” Patsy said quietly. “I can’t say I do or don’t believe in fairies, but I heard what I heard. I knew we’d find Deirdre this morning.”

      The fine hairs stood on the back of Bob’s neck. A retired firefighter walking his golden retriever at sunrise had come upon Deirdre’s body. The police had come and gone, working with a grim efficiency, given Boston’s skyrocketing homicide rate. Now they had another killer to hunt.

      With the city behind them and the boats out on the water and planes taking off from Logan Airport, Bob still could hear the lapping of the tide on the sand. He’d never felt so damn helpless and alone.

      “Deirdre Ita McCarthy.” Patsy crossed her arms on her chest as if she were cold. “It’s the name of an Irish saint, you know. Saint Ita was born Deirdre and took the name Ita when she made her vows. Ita means ‘thirsting for divine love.’”

      Patsy was deeply religious, but Bob had stopped attending mass regularly when he was sixteen and his mother said it was up to him to go or not go. He knew he’d go back to church for Deirdre’s funeral.

      “I’ve never been good at keeping track of the saints.” He tried to smile. “Even the Irish ones.”

      “Saint Patrick, Saint Brigid and Saint Ita are early Celtic saints. Saint Ita had the gift of prophecy. Angels visited her throughout her life. Do you believe in angels, Bob?”

      “I’ve never thought about it.”

      “I do,” she whispered. “I believe in angels.”

      It wouldn’t strike Patsy as particularly contradictory to say in one breath she’d heard a banshee—a solitary fairy—and in another that she believed in angels. If her beliefs brought her comfort, Bob didn’t care. He didn’t know what to tell her about banshees or angels or anything else. Her husband had died of a heart attack four years ago. Now this. “The police will find who took Deirdre from us.”

      “No. They won’t. They can’t.” Patsy shifted her gaze back to the crime scene tape floating in the water. “The police are only human after all.”

      “They won’t rest until they catch whoever did this.”

      “It was the devil who took Deirdre. It wasn’t a man.”

      “Doesn’t matter. If the police have to go to hell to find and arrest the devil, that’s what they’ll do. If I have to do it myself, I will.”

      “No—no, Bob. Deirdre wouldn’t have you sacrifice your soul. She’s with her sister angels now. She’s at peace.”

      Bob suddenly realized Patsy meant the devil literally. He pictured Deirdre with her blond hair and blue eyes, her translucent skin and innocent smile. She was as good as good ever was. She wouldn’t have stood a chance with someone who meant her harm. Devil or no devil.

      He’d miss her. He’d miss her for as long as he lived.

      He pushed back his emotions. It was something he’d need to learn to do if he was going to be a detective and catch people the likes of whoever had killed Deirdre.

      “We don’t want this cretin to hurt someone else.”

      “No, we don’t.” Patsy turned from the water. “But there are other ways to fight the devil.”

      Two hours later, Bob found his sister, Eileen, reciting the rosary on a bench in the shade of a sprawling oak on the Boston College campus, where she had a summer work-study job at the library.

      “I didn’t know you still had rosary beads,” he said.

      “I didn’t, either. I found them in my jewelry box this morning.” She spoke in a near whisper as she held a single ivory-colored bead between her thumb and forefinger. “I haven’t said the rosary in ages. I thought I might not remember, but it came right back to me.”

      Bob sat next to her. His sister was the smart one in the family. She’d returned two days ago from a summer study program in Dublin. No one had called to tell her Deirdre had gone missing. What could Eileen do from Ireland? Why spoil her time there, when they all hoped Deirdre would turn up, safe and sound?

      When news of the discovery of Deirdre’s body reached the O’Reilly household that morning, Eileen pretended nothing had happened and left for work.

      “I’ve just come from the waterfront with Mrs. McCarthy,” Bob said.

      Eileen tensed, as if his words were a blow, and he didn’t go on. Her hair was more dirty blond than red like his, and she had more freckles. She’d never thought she was all that attractive, but she’d always been hard on herself—his sister had no limit to her personal list of faults big and small.

      “There’s nothing the police can do now.” Eileen lifted her eyes from her rosary beads and shifted her gaze to her older brother. “Is there?”

      “They can find Deirdre’s killer. They can stop him from killing again.”

      “They can’t undo what happened.”

      His sister’s left hand trembled, but her right hand, which held her rosary beads,