“I think your security is shot full of holes,” Dillon told Carter. “Too many people, twenty-six restaurants and bars, scores of entrances and exits not only for MPs but staff and workmen.”

“Come now, everyone has a security pass, everyone is checked.”

“Then there’s the river.”

“The river? What nonsense. It’s tidal, Dillon, and the current is lethal. Never less than three knots and sometimes five.”

“Is that so? Then I’m sorry.”

“I should think you would be.” Carter turned to Ferguson. “May I go?”

Ferguson looked at Dillon and the Irishman smiled wearily. “The great conceit of yourself you have, Mr. Carter. A little bet with the man, Brigadier. I’ll turn up on the Terrace on Friday morning when the President and the Prime Minister are here, and all quite illegal. Mr. Carter gets five hundred pounds if I fail, and a five-pound note if I succeed.”

“You’re on, damn you,” Carter told him and held out his hand to Ferguson. “Shake on it.” He started to laugh. “What an amusing little chap you are, Dillon,” and he walked away.

“Do you know what you’re doing, Dillon?” Ferguson demanded.

Dillon leaned over the parapet and looked at the water swirling fifteen feet below. “Oh, yes, I think so, especially if the Chief Inspector here can come up with the right information.”

FERGUSON’S SUITE OF offices was on the third floor of the Ministry of Defence overlooking Horse Guards Avenue, and it was an hour later that Dillon and Hannah Bernstein went into her office.

She sat down at her desk. “All right, what do you want?”

“The biggest expert on the Thames River. Now who would that be? Someone in Customs and Excise or maybe the River Police.”

“I’ll try them both,” she said.

“Good. I’ll go and make the tea while you’re doing it.”

He went into the outer office whistling and put the kettle on. When it had boiled, he made the tea, arranged the cups and a milk jug on a tray, and took it in. Hannah was on the phone.

“Thank you, Inspector.” She put the phone down and sat back as Dillon poured the tea. “How domesticated. That was the River Police telling me who the greatest expert on the river Thames is.” She turned to her computer and tapped the keys. “Subject coming up, Dillon. Not River Police, not Customs, but a London gangster.”

Dillon started to laugh.

THE INFORMATION ROLLED on the screen. “Harry Salter, aged sixty-five, did seven years for bank robbery in his twenties, no prison time since,” Hannah said. “But look at his record from Criminal Intelligence. Owns pleasure boats on the river, the Dark Man pub at Wapping, and a warehouse development worth more than one million pounds.”

“The cunning one, him,” Dillon said.

“A smuggler, Dillon, every racket on the river. Cigarettes, booze, diamonds from Holland. Anything.”

“Not quite,” Dillon told her. “Look what it says. No drug connection, no prostitution, no strip clubs.” He sat back. “What we’ve got here is an old-fashioned gangster. He probably objects to men who swear in front of women.”

“He’s still a gangster, Dillon, suspected of killing other gangsters.”

“And where’s the harm in that if they leave the civilians alone? Let’s see his picture.”

It rolled around and Dillon studied the fleshy face intently. “Just as I expected. Fair enough.”

“Well he looks like Bill Sykes to me,” Hannah said.

“Known associates?”

“Billy Salter, age twenty-five, his nephew.” The information came up on the screen again. “Six months for assault, another six months for assault, twelve months for affray.”

“A hot-tempered lad.”

“And these two, Joe Baxter and Sam Hall, more of the same, Dillon. A very unsavory bunch.”

“Who might just suit my purposes.”

“Except for one thing.”

“And what would that be?”

“The River Police had a tip-off. Salter and his gang will be down river tonight at nine in one of his pleasure boats, the River Queen. There’s a Dutch boat coming in called the Amsterdam. The River Queen will be at anchor off Harley Dock. As the Amsterdam goes past, one of the stewards throws a package across. Uncut diamonds. Two hundred thousand pounds.”

“And the River Police waiting to pounce?”

“Not at all. They’ll be waiting for the River Queen to berth at Cable Wharfe by Salter’s pub, the Dark Man, at Wapping. They’ll pick him up there.”

“What a shame. It could have been such a lovely relationship.”

“Anything else I can do for you?” Hannah Bernstein demanded.

“Not really. I can see you’ve shafted me pretty thoroughly and taken pleasure in it. I’ll just go away and think again.”

AT EIGHT-THIRTY, DILLON was waiting on Harley Dock in an ancient and inconspicuous Toyota van he had borrowed from the vehicle pool at the Ministry of Defence. He was already wearing a black diving suit, the cowl up over his head. Occasionally a boat passed on the river and he sat behind the wheel of the Toyota and watched through a pair of infrared night glasses as the River Queen arrived and anchored. There was movement on deck, two men and two more on the upper deck wheelhouse.

He waited and then there was a noise of engines down river and the Amsterdam appeared, a medium-sized freighter. With his night glasses, he could actually see the man at the rail and the bundle he hurled. It landed on the pleasure boat’s canopy.

The freighter moved on and Dillon was already clamping a tank to his inflatable. He picked up his fins, moved to the edge of the dock, and pulled them on. Then he pulled on his mask, reached for his mouthpiece, and jumped.

HE SURFACED BY the anchor line, pulled off his inflatable and the tank, then his fins, and fastened them to the line. He waited for a moment, then went up hand-over-hand.

He went in through the anchor chain port and crouched on deck, listening. There was the sound of laughter coming from the deck cabin and he went forward, stood and peered through a port hole. Salter was there, his nephew Billy, Baxter, and Hall. Salter was cutting open a yellow life jacket at the table. He took out the cloth bundle.

“Two hundred grand.”

Dillon unzipped his diving suit and took out the silenced Walther. He went to the door, paused, then threw it open and stepped inside.

“God bless all here.”

There was silence, the four of them grouped around the table like some tableau, Harry Salter and his nephew seated, Baxter and Hall standing, beer glasses in their hands.

Salter said, “And what’s your game, then?”

“Open the bundle.”

“I’m fucked if I will. I don’t think you’ve got the bottle to use that thing.”

Dillon fired on the instant, shattering the whiskey glass on the table at Salter’s right hand, doing the same thing to the beer glass Baxter was holding. Billy Salter cried out sharply as a jagged splinter of glass cut his right cheek.

There was silence and so then Dillon said, “More?”

“Okay, you made your point,” Salter said. “What do you want?”

“The diamonds – show me.”

“Tell him to get stuffed,” Billy said, a hand to his cheek where blood flowed.

“Then what?” Salter asked him.

He unfastened the cloth bundle. Inside was a yellow oilskin pouch with a zip fastener. “Open it,” Dillon ordered.

Salter did as he was told and tossed the pouch across where it fell at Dillon’s feet. He picked it up, unzipped the front of his diving suit, and stowed it away. He half turned and took the key out of the door.

Salter said, “I’ll find you. Nobody does this to Harry Salter and gets away with it.”

“And didn’t I hear James Cagney saying that in an old gangster film on the Midnight Movie show on television last week?” Dillon grinned. “I know it doesn’t look it right now, but I’ve actually done you a good turn. Maybe you can do me one sometime.”