"Is something wrong, Davus? You seem to be getting the hang of riding."

"Master? No, the horse is fine." Even as he spoke he tightened his grip on the reins, as if the beast might overhear and rear up just to spite him.

"Is it something else, then?"

"Nothing, Master. Only…" He scanned the empty fields on either side with such a disconcerted look that I followed his gaze, thinking there must be some menace lurking in the clumps of frigid earth and brown grass.

"For Jupiter's sake, what do you see, Davus?"

"Nothing, Master."

"Don't keep saying that! You must see something." "No, Master, that's exactly it. I'm seeing nothing. Nothing at all. And it seems to go on forever." "Are you going blind?"

"No! I can see everything. Except that there's nothing to see!"

I suddenly understood. I couldn't help but laugh at the absurdity of it. Eco frowned and drew his mount closer. "What going on, Papa?"

"Davus has never been outside the city in his life," I said. "Isn't that right, Davus?"

"Yes, Master."

"How old are you, Davus?"

"Nineteen, Master."

"Davus is nineteen years old, Eco, and he has never been on a horse, and he has never stepped foot outside Rome." Eco cursed and rolled his eyes and rode on ahead. "He's angry at me, Master."

"No he isn't, Davus. He misses his wife and he's worried about her."

"Then you're angry at me."

"No, Davus. Forget that I laughed. Don't give it another thought. You'll need all your thinking to stay upright on that horse and to keep track of all the nothing that's going by."

We rode on for a while, the stillness broken only by the clop of hooves against the road. Tufts of steam rose from the horses' nostrils. I took a deep breath, hungry to feel the bite of cold air in my lungs. The empty azure bowl of the morning sky was like crystal. The brown winter earth was like a slumbering giant across whom we made our tiny progress. I was unspeakably glad to be away from Rome.

"He was a very good slave, wasn't he?" said Davus, with a frown so heavy it pulled his chin to his chest. "Who?"

"The bodyguard you had before me. The one who was killed." I sighed. "His name was Belbo. Yes, he was a good slave. A good man."

"I suppose he was stronger than me. Smarter than me, too."

I looked at Davus's hulking arms and shoulders and saw the unhappy befuddlement on his face. "Probably not," I said.

"But I'll wager he knew how to ride a horse. I'll bet he wasn't afraid of an empty field."

"Don't worry about it," I said, as gently as I could. None of this was his fault, after all.

"The sun is up, Eco. The air is cold and clear. There is not another person on the road, not another person in sight. Ah – can you hear that?"

"I don't hear a thing, Papa."

"Exactly. Not even a bird or a cricket. Silence. I believe my faculties are beginning to return. I may actually be able to think again!"

Eco laughed. "Did you ever lose the ability?"

"It's not a joke. Can't you feel it? With every step the horses take us farther from the city, the clearer my head becomes. It's as if I've been in fog, and now it's lifting."

"The haze we left behind in the city was smoke, Papa."

"The haze that's visible, yes. But there's another haze that's settled over Rome. Panic, confusion, deception – no one can think straight. People are behaving like madmen, rushing wildly about, hiding in holes, running from their shadows. It's like a bad dream that won't end. But now I feel like I'm waking up. Don't you feel it, too?"

He looked about, took a deep breath and laughed. "Yes!"

"Good! Perhaps together we can begin to make sense of things."

"Where shall we start, Papa?"

"On this, very spot – but let's go back in time twenty-one days." "Why?"

"Because it was exactly twenty-one days ago that Clodius set out on the Appian Way. I figured it out last night." "And Milo?"

"Milo set out the next day, the day of their fatal encounter – but we'll come to that. Let's begin with Clodius and reconstruct the events as they happened, so far as we know from both Milo and Fulvia." I had not yet shared with Eco all the details of my interview with Fulvia the previous day. "To begin: Fulvia told me that Clodius left their house on the Palatine at about the third hour. Not as early as we did – we set out even before sunrise, before the first hour. But the third hour would have been an early start for a man like Clodius."

"Why, because he was as dissolute as Cicero claims?"

"No, because whenever a man as powerful as Clodius leaves town, even on a short trip, there are always a great many loose ends and last-minute details to be dealt with. I gathered from Fulvia that such was the case with Clodius that morning – hastily scribbled notes, messengers dispatched, and so forth. Finally, Clodius set out. On his way, before he'd even left the Palatine Hill, he paused to look in on a friend who had fallen deathly ill: Cyrus the architect."

"The name's familiar. Will we be questioning him?"

"I'm afraid not. Cyrus died later that very day, not long after Clodius left him. He was an architect to the rich and famous, much sought after. He seemed to have been above politics. Cicero hired him to rebuild his house on the Palatine after it was burned down by the mob. Clodius hired him when he bought that monstrosity of a house from Scaurus, to design all the changes. I gather that Cyrus had been spending a great deal of time at Clodius's house in recent months, overseeing workers, dining with the family."

"So Cyrus worked for both Cicero and Clodius?"

"I gather that he had an artist's temperament – the type that's too talented to take sides. Not only did both Clodius and Cicero use his services, they both gave him legal advice. It seems that Cyrus consulted both of them, separately, when he fell ill and drew up his will – and named both of them among his heirs. After Clodius's farewell visit that morning, Cicero went to see Cyrus, and was with him when he died."

"An architect with a sense of symmetry," noted Eco "You say he was above politics, but I wonder. All the time he was spending at Clodius's house, dining with the family, able to wander about at will – what a splendid eavesdropper he'd have made for Cicero."

"I thought of that. Even if he wasn't a deliberate spy, even in normal conversations Cyrus could have inadvertently given Cicero a great deal of information about Clodius's household and dealings. And Cicero would know just how to extract the information he wanted. But this is merely supposition. We've no cause to think that Cyrus was in any sense a spy. Cyrus merely constitutes a curious link between Cicero and Clodius – just another example of what a small town Rome really is. Cyrus's name comes up again later, which is why I mention him now, but his part in the story is probably insignificant."

"Understood." Eco looked at me shrewdly. "All the same, I'm suspicious of this Cyrus fellow. I shall be keeping a close watch on him – dead or alive."

"That's the spirit!"

"Ugh! Papa, it's not like you to pun."

"None intended. To continue: Clodius paid a last visit to the ailing Cyrus and then set out on the Appian Way. The reason for his trip was some business in the town of Aricia, about fifteen miles from Rome. It's an easy day's journey on horseback, the traditional first night's stop on a trip south, a place with inns and taverns for travellers."

"Clodius had business there?"

"He was slated to address the town senate the next morning. Fulvia didn't seem to know what the occasion was or why Clodius's presence was required. Perhaps it was time for an annual pig festival in Aricia, or a celebration of some local deity. Politicians are always taking trips to outlying towns to court the voters. Clodius happened to be a major property owner in the vicinity; he and Fulvia owned a villa just this side of Aricia. Something to note: Fulvia didn't go with him. That's a little odd. From all I've heard, Fulvia was very much the politician's dutiful wife, and wives generally go along on this sort of trip. While the politician makes friendly jabber with the local magistrates, the politician's wife radiates matronly virtue and shares recipes with the magistrates' wives, or something like that. But Fulvia stayed at home."