Carter jotted down Gabriel’s number, then severed the connection and immediately dialed the operations desk at the National Counterterrorism Center.

“How credible is the information?” the duty officer asked.

“Credible enough for me to be calling you at two thirty-four in the morning.” Carter tried to keep his temper in check. “Get the RSO at the embassy on the phone immediately and tell him to put the entire compound and staff on lockdown until we get a better handle on the situation.”

Carter hung up before the duty officer could pose another inane question and sat there for a moment, feeling utterly helpless. To hell with the NCTC, he thought. He would take matters into his own hands. He dialed the CIA station at the London embassy and a moment later was talking directly to Kevin Barnett, the deputy COS. Barnett, when he spoke for the first time, sounded deeply shaken.

“There’s a group of embassy personnel that does a run in Hyde Park every morning.”

“You’re sure?”

“I’m usually one of them.”

“Who else goes?”

“The chief press officer, the FBI liaison, the Regional Security Officer…”

“Jesus Christ,” Carter snapped.

“It gets worse.”

“How much worse?”

“Elizabeth Halton.”

“The ambassador’s daughter?”

“I’m afraid so.”

“What time do they leave?”

“Seven-fifteen sharp.”

Carter looked at his watch. It was 7:36 in London.

“Get them back inside the embassy, Kevin. Run over to Hyde Park and do it yourself if you have to.”

The next sound Carter heard was the sound of the deputy COS in London slamming down the phone. Carter hung up, waited ten seconds, and called Gabriel back.

“I think I may have a group of diplomats running in Hyde Park at the moment,” he said. “How quickly can you get down there?”

Carter heard another click.

They had entered the park through Brook Gate, headed south along Broad Walk to Hyde Park Corner, then westward along Rotten Row, past the Rose Garden and the Dell. Elizabeth Halton moved to the front of the pack when they reached the Albert Memorial; then, with a DS agent at her side, she steadily increased the pace as they headed north up Lancaster Walk to Bayswater Road. Jack Hammond, the embassy spokesman, slipped past Elizabeth and pushed the pace hard to Victoria Gate, then down the West Carriage Drive to the shore of the Serpentine. As they approached the boathouses, a mobile phone began to ring. It belonged to Chris Petty, the RSO.