Sir Henry had seen Ramage looking at Cargill slumped in the armchair.

"The general joined us recently," he said quietly. "I have the impression that in - how shall I put it? - well, in trying to explain to the French how important he was (no doubt to hurry an exchange, which would be natural enough) he gave them the impression that he was very important to the British government, so the French decided to put him in with the hostages instead of exchanging. I don't know the present rate, but I'd expect a couple of dozen captains for one major-general."

"That would explain it," Ramage said, trying to keep his voice neutral, and Sir Henry smiled.

Ramage's cabin slowly began to empty as Aitken and Kenton started showing the former hostages to their cabins. Orsini was the first to have to stow his trunk and then move out of the midshipmen's berth. Because Ramage had only one midshipman on board, instead of the more usual six or eight, Orsini for a long time had the entire midshipmen's berth to himself. Now eight hammocks had been slung and eight of the hostages were about to be shown how to get in and out of them.

Sir Henry refused Ramage's invitation to use the small dining cabin and took Aitken's. Admiral Lord Smarden had Kenton's cabin and Admiral Keeler had taken over Hill's. The marquis had wanted to sling a hammock among the Marines, who were quartered by tradition between the seamen and the officers, but was finally persuaded to take Martin's cabin.

While the purser worried about feeding the Calypso's distinguished guests (a problem which concerned the purser and first lieutenant a good deal more than the guests, who with the exception of Cargill and the admirals, were as excited at their new surroundings as schoolboys starting off on a picnic), Ramage worked at his desk as his steward collected linen from Ramage's stock for Sir Henry and found a tin water jug and handbasin from somewhere.

Hercules. A man making a joke which he thought would go over his listeners' heads might accidentally give away a good deal. Hercules in Latin, and coming from the Greek Heracles. Ramage cursed his inattention while a tutor had tried to drum Greek mythology into his head. Hercules . . . famous for being so strong. While serving a king (whose name Ramage could not recall), he had to perform twelve labours. Ramage opened a drawer, taking out pen, ink and paper.

He wrote down the first task he could remember - killing a monstrous lion. Then he had to kill the Hydra, the many-headed serpent breathing fire. Catch the Arcadian stag - yes, that was the third, and capturing the Erymanthean boar was another. Cleaning the Augean stables. Catching the man-eating mares of Diomedes. And the Cretan bull. And destroying the Stymphalian birds.

Hmm, that made eight. The Queen of the Amazons came into it - yes, she was Hippolyte, and Hercules had to get her girdle. And get the golden apples of the Hesperides. Ramage dipped his pen in the ink. Two more labours to go - for Hercules, anyway. Yes, the oxen of Geryon: he had to capture them. Then the worst one of the dozen - bring Cerberus up from Hades.

He counted up his list. Yes, twelve, and the only one which looked inviting involved Hippolyte's girdle, though come to think of it that led to a battle and Hippolyte was killed. That was the trouble with Greek mythology . . .

Ramage suddenly realized that the sentry had announced Sir Henry, who was now standing beside him. "Writing up your journal?"

"No, sir," Ramage turned the page round so that the admiral could read it.

"What the devil - oh, twelve. The labours of our old friend Hercules. I've forgotten them all, except cleaning out the Augean stable." The admiral read down the list, nodding his head. "You have a good memory."

He put the list back in front of Ramage. "So you think his reference to the rest of the hostages being in the hands of Hercules might be more than just a joke? After all, he could have said they were awaiting the judgement of Paris ... It might have been the first thing that came into his head."

"Yes, sir," Ramage agreed, "but it's all we have to go on - unless you can think of some other clue. Was there anything?"

Sir Henry shook his head. "No. Nothing, and God knows we were all listening and hoping. No, we all heard 'Hercule', and none of us could make head or tail of it. But I assure you, young fellow, that at the time we took it very seriously."

"But now you don't?"

The admiral slumped down on the sofa. "Now - well, we've all talked about it for so long we're muddled. Pillars of Hercules was the only association we could think of, and that didn't make much sense. Any sense, really."

"That French commandant, sir - was he an educated man?"

The admiral looked up, startled by the question. "Why, yes, come to think of it, he was! More so than the usual run of French officers, who seem to glory in humble beginnings, even if they had to invent them. They must have been farm labourers or butchers or some such thing before they helped in the 'Glorious Revolution'. Yes, the Pitigliano commandant was different: he could have read the classics. Perhaps he was once a teacher. Why do you ask?"

"Just for that reason, sir: if he'd read the classics - knew something of Roman or Greek mythology, in other words - he's more likely to have chosen the name 'Hercules' for a reason."

"Instead of just thinking of a name at random?"

"Yes, sir; there's more likely to be an association. The connection between where the other hostages are imprisoned and Hercules should not be too difficult to guess." Sir Henry looked defeated: his face showed that the riddle of Hercules had never been far from his thoughts from the day the commandant had spoken the word. "My mind is - well, just a whirlpool at the moment. I think and think . . . but to no purpose. I've been thinking of the Pillars, now you come along with the twelve labours . . ."

"Perhaps we should forget it for a few hours," Ramage said. "Then we can tackle it with fresh minds."

"It's hard to forget," Sir Henry said wearily. "But anyway I'm grateful for your efforts so far: I'm sure the Admiralty is more concerned with those you've saved than the others. The wives of flag and field officers are not regarded as very important. Reasonable enough, of course. Tell me," he said, making a determined effort to change the subject, "you know these waters well? I seem to remember Gazettes printing some of your despatches."

"Perhaps when we destroyed some of the French signal towers?"

"No - that was along the French coast. I remember it well. No, wasn't there something round here?"

"We captured some bomb ketches and used them to bombard a port on the other side of Argentario - that was some time ago."

"That was it," the Admiral exclaimed. "What was the name of the place?"

Suddenly Ramage felt the skin of his face grow cold and the hair at the back of his neck seemed to stiffen, as though he was a dog hearing an intruder.

"The modern name is Port' Ercole, sir, but the Latin name was the Port of Hercules."

The admiral sighed. "Now we really begin the twelve labours ..."