“There.” She pointed at the wall at the end of the corridor. “I don’t know why I didn’t see it before!”

What she had seen was a black-and-white photograph in a silver frame. It was hanging right in the middle of the wall with enough space around it to make it stand out. The question was—had Rory hung it there? Or had it been someone else? Was this something we were meant to see?

The photograph showed nine teenagers, all of them wearing the same uniform. It’s funny how people change in ten years—but I recognized them at once: Eric Draper, Janet Rhodes, Mark Tyler, Brenda Blake, Sylvie Binns, Libby Goldman, Rory McDougal, and Tim. Tim looked the weirdest of them all. He’d had long hair then, and acne. Lots of acne. Of course, I wouldn’t have looked too great myself when the picture had been taken—but then I would only have been a baby.

There was one face, however, that I didn’t know. He was standing at the edge of the group, slightly apart—a thin, gangly teenager with curly hair and glasses. He was wearing a windbreaker and had the sort of face you’d expect to see on a train-spotter. “Who’s he?” I asked.

“That’s Johnny!” Brenda replied. “Johnny Nadler. He was one of my best friends . . .”

“And mine,” Libby agreed. “Everyone liked Johnny. We used to hang out with him in the yard.” She walked closer to the photograph. “I remember when this was taken. It was graduation day, when they handed out awards. He came in second in geography. I came in first.”

“Wait a minute,” I interrupted. “Everyone in this photograph is here on Crocodile Island. Everyone except Johnny Nadler!”

“You’re right!” Mark agreed. “Why wasn’t he invited?”

“Because he’s the killer!” Eric snapped. “He’s got to be!”

“But why would Johnny want to kill Rory?” Brenda asked. “The two of them were friends. And every day after school he used to catch the bus with Sylvie—even though it took him eight miles in the wrong direction. That’s how much he liked her.”

“He let Janet cut his hair,” Libby went on. “She accidentally cut a chunk out of his ear, but he didn’t mind. In fact he laughed all the way to the hospital. Johnny wouldn’t hurt anyone.”

“What else can you tell me about him?” I asked.

“He came in second in history as well as geography,” Eric said. “He was really clever.”

“He was always playing with model planes and cars,” Mark added. “He used to build them himself. We always said he’d be an inventor when he left school but in fact he ended up working at a pharmacy. I saw him there once, when I went in to get some ointment.” He blushed. “I had athlete’s foot.”