The limousine turned into Millbank and headed along the Thames toward Lambeth Bridge. Seymour’s mobile phone chirped. He brought it to his ear, murmured a few words, then rang off. “The Americans,” he said by way of explanation. “As you might expect, they’re on war footing. They’ve put the embassy and all its personnel and dependents on lockdown status. They’ve also issued a terrorist travel alert for the United Kingdom, which hasn’t exactly gone over well with Downing Street or the Foreign Office, since it puts us on a par with Pakistan, Afghanistan, and Lebanon. Two hundred investigators from CIA, FBI, and the departments of State and Justice touched down at Heathrow earlier this evening and set up shop at Grosvenor Square. They have an open line to the State Department Task Force in Washington and another one to COBRA, the special committee chaired by the Home Secretary that oversees the British government response to a national emergency such as this.”

“Are they behaving themselves?”

Seymour exhaled heavily. “As well as can be expected, given the circumstances. For now, this is essentially a matter for the British police, which means there’s little for them to do except sit on the sidelines and pressure us to look harder and faster. They’ve made it clear that despite the appalling loss of British life, our first priority must be finding Elizabeth Halton. They’ve also made clear that they have no intention of negotiating for her release.”

“If they do negotiate, no American diplomat anywhere in the world will ever be safe again,” Gabriel said. “It’s a difficult lesson we learned a long time ago.”

“We prefer a more subtle interpretation of that principle. If a good-faith negotiation can bring that woman back alive, then I don’t see the harm in it.”

“I suppose that depends entirely on what you have to give up to get her back.”

Gabriel looked out the window at the Thames. Eight thousand miles of coastline, countless marinas and private airfields… He knew from personal experience that a terrorist with enough intelligence and money could move a hostage almost at will. A year earlier, his wife had been kidnapped from her bedroom in an exclusive British psychiatric hospital. She was on a boat bound for France before anyone even knew she was missing.

“It seems you and the Americans have everything in hand,” he said. “Which means there’s nothing left for me to do but leave London and pretend I was never here.”

“I’m afraid that’s not going to be possible, Gabriel.”

“Which part?”

“Both.”