At the studio flat in Camden, Ahern stood in front of the bathroom mirror and rubbed brilliantine into his hair. He combed it back leaving a center parting, then carefully glued a dark moustache and fixed it in place. He picked up a pair of horn-rimmed spectacles and put them on, then compared himself with the face on the security pass. As he turned, Norah came in the room. She wore a neat, black skirt and white blouse. Her hair was drawn back in a tight bun. Like him she wore spectacles, rather large ones with black rims. She looked totally different.

"How do I look?" she said.

"Bloody marvelous," he told her. "What about me?"

"Great, Michael. First class."

"Good." He led the way out of the bathroom and crossed to a drinks cabinet. He produced a bottle of Bushmills and two glasses. "It's not champagne, Norah Bell, but it's good Irish whiskey." He poured and raised his glass. "Our country too."

"Our country too," she replied, giving him that most ancient of loyalist toasts.

He emptied his glass. "Good. All I need is our box of cutlery and we'll be on our way."

It was around six-thirty when Ferguson left the Ministry of Defence with Hannah Bernstein and told his driver to take him to his flat in Cavendish Square. The door was opened by Kim, the ex-Ghurka Corporal who had been his manservant for years.

"Mr. Dillon has been waiting for you, Brigadier."

"Thanks," Ferguson said.

When they went into the living room Dillon was standing by the open French window, a glass in his hand. He turned. "Helped myself. Hope you don't mind."

"Where have you been?" Ferguson demanded.

"Checking my usual sources. You can discount the IRA on this one. It really is Ahern, and that's what bothers me."

"Can I ask why?" Hannah Bernstein said.

Dillon said, "Michael Ahern is one of the most brilliant organizers I ever knew. Very clever, very subtle, and very, very devious. As I told you, he doesn't let his left hand know what his right is doing."

"So you don't think he's simply shot his bolt on this one?" Ferguson said.

"Too easy. It may sound complicated to you, but I think everything from Quigley's betrayal and death to the so-called accidental explosion of the Telecom van on the President's route was meant to happen."

"Are you serious?" Hannah demanded.

"Oh, yes. The attempt failed so we can all take it easy. Let me look at the President's schedule."

Hannah passed a copy across and Ferguson poured himself a drink. "For once I really do hope you're wrong, Dillon."

"Here it is," Dillon said. "Cocktail party on the Thames riverboat Jersey Lily. The Prime Minister, the President and the Prime Minister of Israel. That's where he'll strike, that's where he always intended; the rest was a smokescreen."

"You're mad, Dillon," Ferguson said. "You must be," and then he turned and saw Hannah Bernstein's face. "Oh, my God," he said.

She glanced at her watch. "Six-thirty, sir."

"Right," he said, "let's get moving. We don't have much time."

At the same moment, Ahern and Norah were parking the Toyota in a side street off Cheyne Walk. They got out and walked down toward Cadogan Pier. There were police cars by the dozen, uniformed men all over the place, and at the boarding point a portable electronic arch that everyone had to pass through. Beside it were two large young men in blue suits.

Ahern said, "Secret Service, the President's bodyguard. I think they get their suits from the same shop."

He and Norah wore their identity cards on their lapels and he grinned and passed a plastic box to one of the Secret Servicemen as they reached the arch. "Sorry to be a nuisance, but there's two hundred knives, spoons, and forks in there. It might blow a fuse on that thing."

"Give it to me and you go through," the Secret Serviceman said.

They negotiated the arch, and he opened the plastic box and riffled the cutlery with his hand. At that moment, several limousines drew up.

"For Christ's sake, man, it's the Israeli Prime Minister," his colleague called.

The Secret Serviceman said to Ahern, "You'll have to leave this box. On your way."

"Suit yourself." Ahern went up the gangplank followed by Norah. At the top he simply slipped through a door and, following a plan of the ship he had memorized, led the way to a toilet area.

"Wait here," he told Norah and went into the men's restroom marked number four.

There was a man washing his hands. Ahern started to wash his hands also. The moment the man left, he went to the red fire bucket in the corner, scrabbled in the sand, and found two Walthers wrapped in cling film, each with a silencer on the end. He slipped one into the waistband of his trousers at the rear and concealed the other inside his uniform blazer. When he went outside he checked that no one was around for the moment and passed the second Walther to Norah, who slipped it into the inside breast pocket of her blazer under the left armpit.

"Here we go," he said.

At that moment a voice with a heavy Italian accent called. "You two, what are you doing?" When they turned, a gray-haired man in black coat and striped trousers was coming along the corridor. "Who sent you?"

Ahern, already sure of his facts, said, "Signor Orsini. We were supposed to be at the buffet at the French Embassy, but he told us to come here at the last minute. He thought you might be shorthanded."

"And he's right." The Head Waiter turned to Norah. "Canapes for you. And wine for you," he added to Ahern. "Up the stairs on the left. Now get moving," and he turned and hurried away.

The Prime Minister and the President had already boarded and the crew were about to slip the gangway when Ferguson, Dillon, and Hannah drew up in the Daimler. Ferguson led the way, hurrying up the gangway, and two Secret Servicemen moved to intercept him.

"Brigadier Ferguson. Is Colonel Candy here?"

A large, gray-haired man in a black suit and striped tie hurried along the deck. "It's all right. Is there a problem, Brigadier?"

"These are aides of mine, Dillon and Chief Inspector Bernstein." Behind him the gangway went down as the crew cast off and the Jersey Lily started to edge out into the Thames. "I'm afraid there could be. The explosion this morning? We now believe it to be a subterfuge. You've had a photo of this man Ahern. Please alert all your men. He could well be on the boat."

"Right." Candy didn't argue and turned to the two Secret Servicemen. "Jack, you take the stern, George, go up front. I'll handle the President. Alert everybody."

They all turned and hurried away. Ferguson said, "Right, let's try to be useful in our own small way, shall we?"

There was music on the night air provided by a jazz quartet up in the prow, people crowding around, mainly politicians and staff from the London Embassies, the President, the Prime Minister, and the Israeli Prime Minister moving among them, waiters and waitresses offering wine and canapes to everyone.

"It's a nightmare," Ferguson said.

Candy appeared, running down a companionway. "The big three will all say a few words in about ten minutes. After that we continue down past the Houses of Parliament and disembark at Westminster Pier."

"Fine." Ferguson turned to Dillon as the American hurried away. "This is hopeless."

"Maybe he's not here," Hannah said. "Perhaps you're wrong, Dillon."

It was as if he wasn't listening to her. "He'd have to have a way out." He turned to Ferguson. "The stern, let's look at the stern."

He led the way to the rear of the ship quickly, pushing people out of the way, and leaned over the stern rail. After a moment, he turned. "He's here."

"How do you know?" Ferguson demanded.

Dillon reached over and hauled in a line, and an inflatable with an outboard motor came into view. "That's his way out," he said. "Or it was." He reached over, opened the snap link that held the line, and the inflatable vanished into the darkness.