Chad Luther managed to pull Cazalet away from the crowd surrounding him. 'The President needs a breather before dinner, ladies and gentlemen. Please.'

'Good for you, Chad,' Cazalet said, as they walked away, Clancy Smith following.

Luther took them back to the sitting room. 'Bathroom through there, Mr President, and if you need a drink I think you'll find everything you need in here.' He opened a panel in the wall and disclosed a superb mirrored bar.

' Chad, as always, you're the perfect host.'

'I'll leave you now.'

Luther went out and Clancy Smith moved into the study and did a quick inspection. He checked the bathroom, then opened the French windows to the terrace. He closed them again.

'Clancy, you're like a hound dog, you never stop sniffing,' Cazalet said.

'That's what I'm paid for, Mr President. There are Secret Servicemen in the garden. I'll be right outside.' He went into the corridor and closed the door.

Cazalet went to the bar and debated whether to indulge. He took a bottle of Scotch from a shelf, then changed his mind and replaced it. Better not. After all, it was going to be a long night. Instead, he took out a pack of Marlboros and selected one. Damn it, a man was entitled to one vice. He lit the cigarette and went and opened the French windows.

There was a half moon and the rain had stopped. That part of the house was very close to the water. There was a lawn, pine trees and a bay almost encircled by two prongs of land. By the water was a boathouse and a wooden jetty, a rather magnificent speedboat moored beside it. He could see the odd couple walking about.

It was really very lovely. He took a deep breath, and a calm and pleasant voice said, 'I wonder if you could oblige me with a light?'

He turned, and Helen Lang moved out of the shrubbery at the bottom of the steps.

She had walked through the garden, strangely sad, as if at the final end of things. Another of her breathless attacks had led her to sit down on a convenient bench. She'd taken two of her pills, and stayed there for a while until she felt better.

It was Cazalet she thought about. It had to be now, before the evening got too late. For a moment, she hesitated, unexpectedly uncertain. Cazalet was a good man, a hero from a rich and powerful family, who could have avoided Vietnam and yet had chosen to serve and been decorated a number of times. Who had become a solid, progressive President, untainted by the arrogance of power. Who had for many years supported a wife dying by inches from leukaemia. A good man. But Peter had been a good man, too. And time was so very short.

She got up, followed the path back to the house, was aware of French windows opening, looked up and saw Cazalet on the terrace. She hesitated, then opened her purse, her fingers brushing the Colt as she produced her silver cigarette case.

'I wonder if you could oblige me with a light?'

'Why, of course.' He came down the steps, his lighter flared.

She held his wrist. 'That's unusual. An old Lee Enfield cartridge.'

'A souvenir from Vietnam, but how did you know it's a Lee Enfield?'

'My husband was a colonel in the British Army. He had a similar one. You won't remember me. We've only touched hands once, at a function in Boston. I'm Lady Helen Lang.'

He smiled warmly. 'But of course. My father and yours did business together back in Boston in the old days. You married an English baronet, as I recall.'

'Sir Roger Lang.'

'Is he here with you?'

'Oh, no, he died two years ago. Our only son was killed serving in Northern Ireland, and my husband was old and frail. The shock was too great for him.'

'I'm truly sorry.'

'Yes, I believe that.'

For some reason he took her hand, and she opened her mouth to speak, and then there came a knocking at the study door. 'Excuse me,' he said, and went up the steps. On the terrace he hesitated and glanced back, but she had faded away as if she had never been there.

Dillon and Blake were standing in a corner of the crowded ballroom when Blake's mobile rang. It was Alice Quarmby.

'I checked Thornton 's background, boss, like you asked. Boy, did I come up with a lulu. Listen to this.'

She went on for several minutes, as Blake's face betrayed no expression. Finally, he said, 'Thanks, Alice, you're an angel.'

'Anything important?' Dillon asked.

'You could say that. Thornton 's our man, all right, and now I know why. I'll explain later. Right now, we'd better find the President.'

'He doesn't seem to be here.'

'There's Luther over there. He'll know where he is,' Blake said.

But when they got there, they found Luther in conversation with Henry Thornton. The two men were laughing, each holding a glass of champagne as Dillon and Blake approached. 'Hey, you two, you're not drinking,' Luther told them.

'Duty calls, Chad,' Blake said lightly. 'This is a colleague of mine from London, Mr Dillon. The President asked to see him when he arrived.'

'He's taking a rest right now.'

The chief of staff held out his hand. ' Mr Dillon, a real pleasure. Your reputation precedes you, sir.'

'That's nice to know.'

Thornton put down his glass and said to Luther, 'I know where the sitting room is, so I'll take them down. This way, gentlemen.'

He pushed through the crowd and led the way to the back corridor, where Clancy Smith sat on a chair beside the door.

'Everything okay, Clancy?'

'Apple-pie order, Mr Thornton.'

The chief of staff knocked, opened the door and led the way in.

Cazalet was still on the terrace as they crossed to the open French windows.

'Anything wrong, Mr President?' Thornton asked.

'No, I was just talking to a very unusual woman, but I seem to have lost her,' and then he smiled. 'Why, Mr Dillon.' He clasped his hand warmly. 'A pleasure to see you.'

'Not this time, Mr President, I think you really would rather kill the messenger than listen to what Blake and I have to say.'

'That bad?' Cazalet leaned against the balustrade. 'Then I'd better have a cigarette on it.' He took out a Marlboro and Dillon gave him a light from his Zippo. 'Okay, gentlemen, let's hear the worst.'

And below, concealed in the shrubbery, Helen Lang listened.

Blake said, 'You know all about the Sons of Erin, Mr President, just as we do. We always felt the killings to be the work of one person. We also felt there had to be a strong reason.'

Cazalet nodded. 'Acts of revenge for some kind of terrible act.'

'Yes, well, now we know just how terrible.' He turned to Dillon. 'Sean?'

'For years, information from British Intelligence was passed on by our White House connection to the Sons of Erin and Jack Barry. Because of such information, three years ago the members of a British Army undercover unit were all killed by Jack Barry and his boys. The commander was a Major Peter Lang. He was tortured, murdered and disposed of in a cement mixer.'

'A truly appalling crime,' Blake said.

'Let me get this straight,' Cazalet said. 'Major Peter Lang?'

'That's right.'

'But I've just been talking to a Lady Helen Lang out here. She told me her son was killed in Ireland.'

'Yes, sir,' Dillon said. 'She's his mother.'

'And she's the person responsible for the destruction of the Sons of Erin,' Blake said.

The President looked stunned, and Thornton jumped in. 'Come on, that's past belief. One woman? An old lady? I can't believe it.'

'I'm afraid there's little doubt,' Blake told him.

'Yes, she did rather well, when you think of it,' Dillon said. 'Only Jack Barry and the Connection are left now.'

Thornton said, 'What happens now? I mean, if this story is true, why isn't this woman under arrest?'

The President said, 'Blake?'

'I said there's little doubt. I'm also afraid there's no hard proof, Mr President. For obvious reasons, it would be better to handle this thing quietly. And there is something else, sir.'