“Yes, sir,” Cramer replied. The ‘sir’ slipped out naturally and the Colonel smiled. He left the office, leaving Joker deep in thought, staring at the empty whisky bottle.

Cole Howard caught the morning flight to Washington, DC. As he sat in the front row of the economy section he flicked through the pack of Trivial Pursuit cards he’d brought with him. “You like playing?” asked his neighbour, an elderly woman in a neck brace. “My nephews bought me a set last Christmas. I play it all the time.”

“I dislike the game intensely,” Howard answered. The woman looked shocked as if Howard had sworn at her and she buried her head in a magazine. Howard began to go through the cards, memorising the answers.

There was a queue for taxis when he arrived at Washington Dulles International Airport but he took the wait good-naturedly. The FBI laboratories were half an hour’s drive from the airport, during which time he worked his way through another two dozen cards. On arrival, he clipped his FBI badge to his breast pocket and flashed his identification at the security guards at reception. He was told that the lab he was looking for was on the second floor. There he asked for Dr Kim. He wasn’t surprised when a woman came out to meet him, because they’d spoken several times on the phone, but he was surprised at how young and attractive she was. She was Oriental, with waist-length hair which she wore as a single braid. She had razor-sharp cheekbones and a small, delicate mouth and oval eyes which narrowed almost to slits when she smiled. “Dr Kim,” said Howard, as they shook hands. His hand seemed to dwarf hers. It was as delicate as a six-year-old’s, with nails painted a deep red.

“Call me Bonnie,” she said. “My lab’s this way.” Her high heels clicked on the tiled floor as they walked. Even with the heels the top of her forehead barely reached his shoulders, and Howard was only a little over six feet tall. She took him past several doors and into a long, thin laboratory which had white benches lining the walls and a small cubbyhole of an office at the end. On the benches in the lab were several IBM computers and racks of VCRs and monitors. One of the VCRs had been opened up and she’d been doing something with a circuit board and a soldering iron. The iron was still on and she pulled out the plug.

She poured him a cup of coffee from a percolator and sat on a swivel chair facing one of the monitors. She opened a drawer under the bench and handed him a pale blue file.

“These are prints of what I’ve been able to achieve so far,” she said. “But I wanted you to see the video with me, too. I have some suggestions which might help.”