“In what way, may I ask?”

“We’re all bound by our acquaintance with Noah Perlis. Your father knew Perlis, didn’t he?”

Diego didn’t miss a beat. “As a matter of fact he didn’t. Noah was my friend. We’d go to the casino-the Vesper Club-and gamble the night away. This is what Noah liked to do best when he was in London. The moment I knew he was coming I’d set it all up-his credit line, the chips.”

“And, of course, the girls.”

Diego grinned. “Of course the girls.”

“Didn’t he want to see Tracy-and Holly?”

“When they were here, but most times they weren’t.”

“You were a foursome.”

Diego frowned. “Why would you think that?”

“Judging by the photos in Noah’s flat.”

“What are you implying?”

Something almost imperceptible had crept into Diego’s demeanor. A tension akin to a subtle ripple emanating from the core of him. Bourne was pleased that his probing had struck a nerve.

Bourne shrugged. “Nothing, really, other than in those photos you all looked very close.”

“As I said, we were friends.”

“Closer than friends, I would think.”

At that moment Diego glanced down at his watch. “If you fancy a bit of a flutter, now’s the time to take ourselves to Knightsbridge.”

The Vesper Club was a very posh casino in London’s very posh West End. It was one of those discreet affairs, hardly noticeable from the street, the polar opposite of the exclusive velvet-rope nightclubs in New York and Miami Beach that revel in their crassness.

Inside it was all butter-soft leather banquettes at the restaurant, a long, snaking brass-and-glass, neon-lit bar, and a number of gaming rooms clad in marble, mirrors, and stone columns with Doric capitals. They passed among the slots. Off to one side was the electronic gaming room whose high-decibel rock music and neon lights seemed to blink Go! Bourne peered in, saw that it was patrolled by a guard. He guessed the club figured the younger clients were more apt to get rowdy than the older, more established ones.

They went down several steps into the more sedate but no less opulent main gaming area, featuring all the usual suspects: baccarat, roulette, poker, blackjack. The oval room was filled with the low buzz of bets being made, roulette wheels spinning, the calls of the croupiers, and the ubiquitous clink of glassware. They wound their way through this expanse to a green baize door guarded by a large man in a tuxedo. The moment he caught sight of Diego, he smiled and gave a small deferential nod.

“How are you this evening, Mr. Hererra?”

“Quite all right, Donald.” He gestured. “This is my friend Adam Stone.”

“Good evening, sir.” Donald opened the door, which swung inward. “Welcome to the Vesper Club’s Empire Suite.”

“This was where Noah liked to play poker,” Diego said over his shoulder. “Only high stakes, only expert players.”

Bourne looked around at the dark walls, the solid-marble floor, three kidney-shaped tables; the hunched shoulders and concentrated expressions of the men and women who sat around the green baize analyzing the cards, sizing up their opponents and placing their bets accordingly. “I wasn’t aware that Noah had the kind of money to be a high-roller.”

“He didn’t. I staked him to it.”

“Wasn’t that risky?”

“Not with Noah.” Diego grinned. “When it came to poker he was an expert’s expert. Before an hour went by I’d get my money back and then some. I’d go and play with the profit. It was a good deal for both of us.”

“Did the girls come here?”

“What girls?”

“Tracy and Holly,” Bourne said patiently.

Diego looked thoughtful. “Once or twice, I suppose.”

“You don’t remember.”

“Tracy liked to gamble, Holly didn’t.” Diego’s shrug was an attempt to conceal his growing discomfort. “But surely you know this already.”

“Tracy didn’t like to gamble.” Bourne kept any hint of accusation out of his voice. “She hated her job, which caused her to gamble almost every day.”

Diego turned back to him, a look of consternation on his face, or was it fear?

“She worked for Leonid Arkadin,” Bourne continued. “But surely you knew this already.”

Diego licked his lips. “Actually, I had no idea.” He looked as if he wanted to sit down. “But how… how is this possible?”

“Arkadin was blackmailing her,” Bourne said. “He had something on her, what was it?”

“I… I don’t know,” Diego said in a shaky voice.

“You need to tell me, Diego. It’s vitally important.”

“Why? Why is it vitally important? Tracy is dead-she and Holly are both dead. And now Noah, too. Shouldn’t they all be left in peace?”

Bourne took a step toward him. Though he lowered his voice, it was full of menace. “But Arkadin is still alive. He was responsible for Holly’s death. And it was your friend Noah who murdered Holly.”

“No!” Diego stiffened. “You’re wrong, he couldn’t possibly-”

“I was there when it happened, Diego. Noah pushed her off a flight of steps at the top of a temple in East Bali. That, my friend, is fact, not the fiction you’ve been feeding me.”

“Drink,” Diego said in a voice made thin and hoarse by his consternation.

Bourne took him by the elbow and walked him over to the small bar at the rear of the Empire Suite. Diego lurched on stiff legs as if he were already drunk. As soon as he collapsed on a stool he ordered a double whiskey-no refined sherry for him now. He drank the whiskey off in three long gulps, then asked for another. He would have downed all of that, as well, if Bourne hadn’t pulled the glass out of his unsteady hand and set it down on the black granite bartop.

“Noah killed Holly.” Diego was slumped over, staring into the depths of the whiskey, into a past that he’d thought he knew. “What a fucking nightmare.”

Diego did not seem to be a man prone to foul language. He was clearly out of his element, which indicated that he wasn’t privy to his father’s illicit arms trafficking. Neither, apparently, did he know what Noah had done for a living.

Suddenly his head swung around and he looked at Bourne. “Why? Why would he do that?”

“He wanted something she had. Apparently she wouldn’t give it to him voluntarily.”

“So he killed her?” Diego looked incredulous. “What kind of man would do something like that?” He shook his head slowly and sadly. “I can’t conceive of anyone wanting to harm her.”

Bourne noticed that Diego hadn’t said, I can’t conceive of Noah wanting to harm her. “Clearly,” he said, “Noah was not who you thought he was.” He refrained from adding, Neither was Tracy.

Diego grabbed the glass and finished off the second double. “Good God,” he whispered.

Very gently Bourne said, “Tell me about the four of you, Diego.”

“I need another drink.”

Bourne ordered him a single this time. Diego lunged for the glass like a life jacket thrown to a drowning man. At one of the tables a woman in a glittery gown cashed in, rose, and walked out. Her place was taken by a man with the shoulders of a football player. A heavyish older woman with frosted hair, who had apparently just come in, sat down at the middle table. All three tables were full up.

Diego took two convulsive swallows of whiskey, then said in a voice bled dry, “Tracy and I had a thing, nothing serious, we saw other people-at least she did. It was very off-and-on, very casual. We had a few giggles, nothing more. We didn’t want it to disturb our friendship.”

Something in his voice alerted Bourne. “That’s not all of it, is it?”

Diego’s mournful expression deepened, and he looked away. “No,” he said. “I fell in love with her. I didn’t mean to, I didn’t even want to,” he added, as if it had been within his power to choose. “She was so nice about it, so kind. But still…” His voice drifted away on a tide of sad memories.

Bourne thought it time to move on. “And Holly?”