"Absolutely none," Pitt said quietly.

Gunn stared at Pitt for a full ten seconds, his face expressionless. "You realize the seriousness of what you're asking me? Most of the men aboard this ship are scientists, not commandos. They're tigers with a salinometer, a nansen bottle or a microscope, but their skill at knifing another man in the guts or shooting a barbed spear into a navel leaves much to be desired."

"What about the crew?"

"All good men to have on your side in a barroom brawl, but like most professional seamen, they have an unhealthy dislike for any activity below the surface. They can't, or rather won't, put on a face mask and dive." Gunn shook his head. "I'm sorry Dirk, you're asking too much—"

"Come off it," Pitt snapped rudely. "This isn't the Little Big Horn and I'm not asking you to send the Seventh Cavalry against Sitting Bull and the Sioux nation. Look, not fifty miles from here a Minerva Lines freighter is churning across the Aegean with a cargo that is as lethal as any nuclear bomb. If that amount of heroin were dumped on the market in the States, our grandchildren would still be suffering from the cultural shock waves. It's a nightmarish thought."

Pitt paused, letting his words sink in. He lit a cigarette and then continued.

"The Bureau of Narcotics and the Customs Department will be waiting. They've set a trap. If, and that's a big if, all goes well, the heroin and the smugglers, plus half the illegal drug sellers in the States, will be neatly scooped up and salted away behind bars."

"Then what's the problem?" Gunn pressed. "Where do the divers fit into the picture?"

"Let's just say I have a nagging doubt. Von Till hasn't come within a nautical mile of being caught with the goods, so to speak, for decades. Legally, our government agents can't board the cargo ship until it touches the United States' continental shelf, three weeks away. By then von Till might sense that INTERPOL is behaving overly cagey. Rather than cooperate with the good guys and sail into the trap, he'd have to reroute the ship at the last minute or else dump the heroin in the Atlantic. That leaves the narcotic agents and the customs inspectors standing around with nothing to do but play with themselves. The only sure way, the safe way, is to stop the ship now, before it leaves the Mediterranean."

"You're the man who said it—legally it can't be done."

"There is one way." Pitt drew on the cigarette, then slowly let the smoke trickle through his nose. "Prove a solid case against von Till and Minerva Lines before morning."

Gunn shook his head again. "Even then, boarding a ship in international waters, particularly a ship that is registered to a friendly nation, can lead to political repercussions. I doubt if any country would want to touch it."