McGuffin looked around the room. If he could have seen a telephone I reckon he would have used the cord to strangle Tim and then made his call uninterrupted. But whoever was waiting for him outside had him cornered. Time was running out. He had no choice. “Okay,” he said. “I’ll tell you.”

He sat down opposite Tim and took out a cigarette. “You got a light?” he asked.

Tim switched on his desk light. McGuffin scrunched his cigarette on the desktop. He seemed to have gotten a lot older in the last few minutes. “Listen,” he said. “I’m an agent. It doesn’t matter who I work for.”

“Who do you work for?” Tim asked.

“It doesn’t matter. I’m on the track of a man called Charon. He’s a killer, an assassin, the head of a murder organization that’s bigger than General Motors.”

Tim was puzzled. “Charon?” he asked. “What sort of name is that?”

“It’s a code name,” McGuffin explained. “It comes out of the Greek myths. You ever hear of Hades, the Greek underworld? In the old legends, it’s where people went when they died. Charon was the person who took them there. He was the ferryman of the dead.”

The sun must have gone behind a cloud. For the first time that summer I felt cold. Maybe it was the breeze coming in through the bullet hole.

“Nobody knows who Charon really is,” McGuffin went on. “He can disguise himself at the drop of a hat. They say he’s got so many faces his own mother wouldn’t recognize him.”

“Do you know his mother?” Tim asked.

“No.” McGuffin took a deep breath. “There’s only one way to recognize Charon,” he said. “He’s lost a finger.”

“Whose finger?” Tim asked.

“His own. He only has nine fingers.”

Tim smiled. “So that’ll help you finger him!”

McGuffin closed his eyes for a few seconds. He must have hoped he was dreaming and that when he opened them he’d be somewhere else. “Right,” he said at last. “But I’ve got no time. Charon is about to kill a Russian diplomat called Boris Kusenov.”

“I’ve heard of him,” I muttered. And it was true. I’d seen the name in the last newspaper I’d read. It had been underneath my chips.

“If Kusenov dies, that’s it,” McGuffin went on. “The Iron Curtain goes back up. There’ll be another arms race. Maybe even war . . .”

“As bad as that?” Tim asked.

“I’m the only man who can stop him. I know when Charon plans to kill him. And I know how. I’ve got to make that call.”

Tim shrugged. “That’s too bad, McNothing. We don’t have a phone.”

“No phone . . .” For a moment I thought he was going to murder Tim. He’d told us everything. And he’d gotten nothing for it. His hands writhed briefly. Maybe he was imagining them around Tim’s throat.

“There’s a phone booth around the corner, in Skin Lane,” I suggested.