Ramage called the Marine sentry to pass the word for Gilbert. A couple of minutes later he told the Marine to send for Midshipman Orsini as well: it was now two or three years since Paolo had escaped from Volterra and made his way to England by way of Naples, but he might remember some French regulations which could help prevent mistakes.

How much to tell them? It would be asking a lot of Gilbert not to relate to the rest of his mess (Jackson, Stafford, Rossi and the other three Frenchmen) why the captain had sent for him. Orsini would keep his mouth shut because, apart from anything else, it concerned his own country, and he would not want to risk any slips. Which led to the decision whether or not to take him.

Paolo might by now be the new ruler of Volterra: that was the first consideration. If Gianna was dead, he would certainly be by right of succession, even though Volterra was at the moment occupied by the Army of France.

If Paolo was captured and identified by the French, his throat would be cut - having murdered Gianna, the French would be delighted to dispose of the Marchesa's nephew and successor. Yet one must consider that Paolo knew all this countryside like the back of his hand. Italian was, of course, his native tongue but, being an educated young man, his French was fluent and his English marred by only a very slight accent.

So, Ramage thought, by not taking him I lose a guide, a young man speaking French and Italian, and perhaps more important, one who looks French or Italian: a sallow skin, jet-black hair, a narrow face which anyone who had travelled would at once identify as Italian or Spanish. A Mediterranean face, in fact.

What would Gianna have expected? Suddenly he could see her face and hear her voice: for a moment she seemed to be in the cabin with him: a memory, or a ghost, but most certainly Gianna, and at her most decisive. "Paolo has been in action with you a dozen times. More, in fact. A French roundshot could have knocked his head off at any time. One is, my dear Nicholas, just as dead from a roundshot as a dagger thrust - or the musket balls of a French firing squad. And, dear Nicholas, can you bear the reproachful look in the boy's eyes when you tell him you are not taking him?"

Gianna's voice was so firm, so determined, so real in his imagination that the sentry's knock bringing him back to reality made him blink, still expecting her to be there.

"Send them in!" he called, and waved Paolo and Gilbert to sit down. Paolo sat in what had become known as "Southwick's chair" and Gilbert perched on the edge of the settee, combining the discomfort of a servant sitting in his master's presence (a hangover from the château) with the nervousness of a seaman unexpectedly summoned to the captain's presence.

Ramage then realized that with the Calypso just off the Italian coast, even if both Paolo and Gilbert bellowed the Admiralty's secret orders through speaking trumpets, there was no enemy close enough to hear them.

He spoke first to Paolo. "You remember Pitigliano?"

Paolo looked startled, and then said: "Near Orvieto - a hill town?"

Ramage nodded and turned to Gilbert. "The road running along the coast here and down to Rome is the Via Aurelia - you've heard of it?"

"Only because it's one of the great roads down which Julius Caesar marched. One of them crosses the Rubicon, doesn't it, sir?"

"That's it - I hardly expected you to know about the Rubicon, though."

"I don't, sir," Gilbert admitted. "Just the phrase."

Ramage glanced at Paolo. "Go on, you explain it!"

Paolo grinned broadly because, second only to the sea and naval tactics, his interest was (as Ramage knew) the complex history of the Roman Empire. "Crossing the Rubicon - well, in English it means reaching a line where you have to make an important decision one way or the other. If you stay your side, you're safe: if you cross, you're committing yourself to something drastic."

"Go on," Ramage urged, "let's have the details. Why is it called the Rubicon, this line of yours?"

"It's a small river running into the Adriatic between Ravenna and Rimini, where the Via Emilia and Via Flaminia meet. Not deep or fast. But we have to go back to 59 bc, when Julius Caesar was neither famous nor feared: he was simply a famous man's nephew with little experience as a soldier. He was governor of an area of what is now northern Italy and southern France. The Helvetii, in what is now Switzerland, were causing trouble so he went up to Geneva to deal with them.

"But he knew fame and fortune in the Roman Empire came only to victorious generals, so Caesar carried on north to defeat the Gauls (the French of today), the Germans and the Belgae - three hundred thousand barbarians living in northern Gaul (the Netherlands of today). He beat them and went on to cross the Channel and conquer Britain.

"By the time he was ready to return to Italy - after fighting many more battles - he was famous and his nine legions were devoted to him. (They were not paid by the government: their leader, in this case Caesar, let them plunder, so a successful general always had loyal troops!)

"Left in Rome all this time," Paolo continued - and Ramage saw that the youth had slipped back more than eighteen centuries, so that he was a centurion marching at the head of his hundred men, part of the six hundred who made up a cohort, ten of which, six thousand men, made up a legion - "was Pompey, a great general who had conquered Spain but had done no fighting for a dozen years.

"Obviously the two of them had to be rivals: rivals in a competition with the Roman Empire the prize. Well, Caesar was coming back from Gaul with nine legions of men who had been victorious everywhere. Pompey had ten legions - but unfortunately for him, seven were away in Spain.

"By January 49 bc, Caesar and his legions had reached the northern bank of the Rubicon in the march back to Italy. The southern side of the river was Pompey's territory. The question facing Caesar was, should he cross the Rubicon and attack, or should he stay where he was. Obviously the stakes were enormous. Well, he did cross - and Pompey retreated right down the coast to Brindisium - Brindisi - and fled across the Adriatic. Within ten weeks of crossing the Rubicon, Caesar ruled the Roman Empire. So, mon cher Gilbert, when you have to make a great decision you've reached the banks of the Rubicon: when you make it and carry it out, you've crossed . . . such a muddy river it is, too."

Gilbert nodded and, turning to Ramage, asked quietly: "Have we reached a Rubicon, sir?"

"We're approaching it," Ramage said, "but for the moment we're concerned with the Via Aurelia, and in particular a small stretch where it passes Monte Argentario, which looks from the sea like a small and mountainous island but which is linked to the mainland by a couple of causeways."

Paolo had looked up sharply. "Monte Argentario, sir?"

"You remember it, then, even though it's not now part of the Roman Empire! Yes, Port' Ercole at the southern end is where we had our little affair with the bomb ketches, but now we use Argentario only as a landmark - the northern end, this time. More precisely, where that northern causeway meets the Via Aurelia."

"Surely that's where the road to Pitigliano branches off, sir?"

"Exactly. And about thirty miles along that road is Pitigliano."

"It's a rotten road, from memory. Not much more than a track, sir. Marsiliana is about a third of the way, Manciano about two thirds and then you reach Pitigliano, with Monte Labbro and Monte Amiata over on your left. Why - may I ask why - are we interested in Pitigliano, sir? It's so far inland - for a cutting out expedition, anyway!"

"Their Lordships don't think so," Ramage said drily. "I have their orders here." He tapped a drawer. "We march, not row," he said grimly. "Thirty miles there and thirty miles back, only we'll have company when we return."