“I was buzzing off Linda Dwyer for a while, when we were like sixteen—remember the Dwyers, in Number One? We used to meet in her back garden at night, so she could stop me putting my hand up her top. That wall”—he pointed to the bottom of the road—“on the other side, it’s smooth. No footholds. You can only get over it at the corners, where you can use the other wall to pull yourself up. That takes you into the back gardens.”

“You’re a fountain of knowledge,” I said. “Did you ever get into Linda Dwyer’s bra?”

Kevin rolled his eyes and started explaining Linda’s complex relationship with the Legion of Mary, but I was thinking. I had a hard time picturing a random psycho killer or sex attacker hanging around back gardens on a Sunday night, hoping forlornly that a victim would stroll by. If someone had nabbed Rosie, he had known her, he had known she was coming, and he had had at least the basics of a plan.

Over the back wall was Copper Lane: a lot like Faithful Place, only bigger and busier. If I had wanted to arrange any kind of clandestine meeting or ambush or what-have-you along the route Kevin had pointed out, especially a clandestine meeting that might involve a struggle or a body dump, I would have used Number 16.

Those noises I had heard, while I waited under the lamppost shifting from foot to foot to keep from freezing. A man grunting, stifled squeaks from a girl, bumping sounds. A teenage guy in love is a walking pair of nads wearing rose-colored glasses: I’d taken it for granted that love was everywhere. I think I believed Rosie and I were so wild about each other that it got in the air like a shimmering drug, that night when everything was coming together, and swirled through the Liberties sending everyone who breathed it into a frenzy: wrecked factory workers reaching for each other in their sleep, teenagers on corners suddenly kissing like their lives depended on it, old couples spitting out their falsies and ripping off each other’s flannel nighties. I took it for granted that what I was hearing was a couple doing the do. I could have been wrong.

It took a mind-bending effort to assume, just for a second, that she had been coming to me after all. If she had, then the note said she had very probably made it along Kevin’s route as far as Number 16. The suitcase said she had never made it out.

“Come on,” I said, cutting off Kev, who was still going (“ . . . wouldn’t have bothered, only she had the biggest rack in the . . .”). “Let’s go play where Mammy said we shouldn’t.”