“Right, guv,” the cabbie said. “It’s your money; I’ll follow them to Cornwall, if you like.”

“I doubt if they’ll go that far.”

Lance’s cab set off. Stone’s driver reversed for a few yards, then drove up another mews. Stone thought the man had lost the other cab, until it appeared ahead of them. “Very good,” he said to the driver.

“It’s what I do,” the cabbie said. “You know about The Knowledge?” Lance’s cab turned into Park Lane, and Stone’s followed.

“What knowledge is that?”

“The Knowledge is what every London cabdriver has to have before he gets a license. You drive all over town on a motorbike for a year or two, taking notes on addresses, public buildings, pubs, theaters and tube stops—whatever you see; you go to classes at night; and finally you take the exam. A question would be, like, ‘A passenger wants to go from Hampstead Heath to Wormwood Scrubs Prison. Describe the shortest route, and name every cross street, public building, and tube stop along the way.’ Miss one cross street, and you’ve missed the question. Miss too many questions, and you’ve failed the exam. Get it right, and you have The Knowledge, and you get your license.”

Lance’s cab drove around Hyde Park Corner, through Belgrave Square, on to Sloane Square, and started down the King’s Road. Stone glanced at side streets as they passed and wondered if he could ever memorize them all. “That’s pretty impressive,” he said.

“I had a mate once, went through all that, passed The Knowledge, got his license, then he went out to celebrate that night, had a lot to drink, and got stopped by the police on the way home and Breathalyzed. Lost his license; he’d taken two and a half years to get it, and he kept it only a few hours.”

“Poor fellow,” Stone said. They were past World’s End now, continuing down the King’s Road, past dozens of antique shops. A large, black car overtook Stone’s cab and drove on.

“Who’s in the other cab?” the cabbie asked. “If you don’t mind my asking.”

“My wife’s boyfriend, I think,” Stone replied.

“Don’t you worry, guv, I won’t lose the bastard.”

Up ahead, Lance’s cab was signaling a left turn. The black car turned, too. It was starting to look familiar to Stone. Lance’s cab approached a large building that had probably once been a warehouse but now bore a large sign declaring it to be an antiques market. Down the block, Lance’s cab came to a halt, and its three occupants got out. The black car stopped half a block behind them.

“Stop here,” Stone said. The cabbie stopped. Stone watched as two large, swarthy men got out of the back of the limousine and followed Lance and his companions into the building.