Seymour had taken the call on a device reserved for his private communications. Next to it was his direct line to Amanda Wallace at Thames House. He hesitated for a few seconds, then lifted the receiver to his ear. It rang without dialing. Amanda’s voice came instantly on the line.

“Graham,” she said genially. “What can I do for you?”

“I’m afraid that operation of mine has touched British soil.”

“In what form?”

“A car headed toward the center of London.”

After hanging up, Amanda Wallace boarded her private elevator and rode down to the operations center. She settled into her usual chair on the top deck and snatched up a telephone that reconnected her to Graham Seymour.

“Where are they?” she asked.

Ten tense seconds elapsed before Seymour answered. The BMW was approaching the Hammersmith flyover. Amanda Wallace ordered one of the techs to feed the CCTV image into the center video screen. Twenty seconds later she saw the blue BMW speed past in a blur of wet traffic.

“What kind of car does Allon have?”

Seymour answered as the Passat flowed through the shot, three cars behind the BMW. Amanda ordered the op center techs to track the movements of the two vehicles. Then she rang the chief of A4, MI5’s covert surveillance and operational arm, and ordered him to put the cars under physical watch.

Other senior staff were now rushing into the op center, including Miles Kent, the deputy director. Amanda asked him to run a check of the BMW’s registration. In less than a minute, Kent had an answer. There was no record of AG62 VDR in the database. The registration plates were false.

“Find out if any blue BMWs have been reported stolen,” snapped Amanda.

This search took longer than the first, nearly three minutes. A BMW of the same make and model had gone missing four days earlier in the seaside town of Margate. But it was gray, not blue.

“They must have painted it,” said Amanda. “Find out when it was left at Heathrow, and get me the video.”

She looked at the center screen. The BMW was passing through the intersection of West Cromwell Road and Earl’s Court Road. The Passat was three cars behind. Gabriel Allon, whom Amanda had met just once, was clearly visible in the passenger seat. So was the man behind the wheel.

“Who’s the driver of the chase car?” she asked Graham Seymour.

“It’s a long story.”

“I’m sure it is.”

The BMW was approaching the Natural History Museum. The surrounding pavements were crowded with schoolchildren. Amanda squeezed the telephone so tightly the blood drained from her knuckles. When she spoke, though, she managed to sound calm and assured.

“I’m not prepared to allow this to continue much longer, Graham.”

“I’ll support whatever decision you make.”