“Or Parthia,” said Trajan, stroking his chin and gazing at the vast empire that dominated the far-eastern portion of the map.

“There are dangers, of course,” said Hadrian. “Even the Divine Augustus was thwarted when he tried to make slaves of the Germans. And no Roman has yet succeeded in taking Parthia; the empire is simply too big and too powerful. Dacia seems ripe for the picking, but that, too, presents a risk. Domitian did his best to get the better of King Decebalus and repeatedly failed.”

“That’s because Domitian was a military genius only in his imagination,” said Plotina.

Hadrian nodded. “Certainly, Caesar is a far better military man than Domitian, but is he not also a better diplomat? Rather than attack King Decebalus head-on, perhaps the best strategy would be to win over the king’s neighbours and allies, using statecraft to isolate the Dacians before directly confronting them.”

“The less blood shed by Romans, the better,” Plotina agreed. “Never forget what becomes of Roman soldiers when they’re captured by the Dacians. They’re handed over to the Dacian women, and the tortures inflicted on those poor men are the stuff of nightmares. If the way of conquest can be made easier by diplomacy, all the better.”

“Might we not also send agents to tamper with the Dacians’ religious ceremonies?” suggested Hadrian.

“How would that be of use?” asked Trajan.

“The Dacians’ most important religious ceremony is an event held every five years, at which a youth is sacrificed to their god, Zalmoxis.”

“I’ve never heard of him,” said Plotina.

“Nor have most people outside Dacia,” said Hadrian. “Zalmoxis was once a man, a Dacian who became a slave and then a disciple of the Greek philosopher Pythagoras. After Pythagoras freed him, Zalmoxis returned to Dacia and became a healer and religious teacher in his own right. He died but was resurrected, and preached to the Dacians about the immortality of the soul before he finally left this world for the next.”

“Don’t the Christians also worship a man who became a god?” said Trajan. “Or is it a god who became a man?”

“There are similarities in the two religions,” acknowledged Hadrian, “but the worship of Zalmoxis is much older. The most important ceremony is held once every five years in a cave in the holy mountain of Kogaionon, where Zalmoxis spent three years in seclusion. A chosen youth is cast onto the points of three lances. His mission is to die, and then to deliver the requests of the Dacians to Zalmoxis in the other world. But sometimes the youth fails to die. If that happens, the messenger is deemed unworthy and another is chosen, but the omen is very bad.”

“When does the next such ceremony take place?” asked Trajan.

“According to our spies, the next five-year ceremony will take place in just a few months. This has caused me to wonder, Caesar, if Roman agents inside Dacia might somehow sabotage the ceremony, and by doing so spread doubt and dissension among the Dacians.”

Trajan laughed heartily and slapped his knee. “Little Greek! Only you could sift through all that foreign gibberish and find a way to use it to our advantage. Perhaps that endless education of yours will turn out to be more useful than I thought. I love this idea! By all mean, yes, instruct our agents in Dacia to make a shambles of the upcoming ceremony.”

“And if they should be uncovered?” asked Plotina.

“We’ll disavow any knowledge. Decebalus will assume the agents originated from enemies within his own court.”

“While the Dacian women have their way with the poor agents,” said Plotina.

“Such men know the risks they take in return for the generous rewards I give them,” said Trajan. “Ah, but this discourse on Zalmoxis reminded me of the Christians.” He waved to a secretary, who brought him a scroll. “I’ve been asked by a provincial governor for official instructions on what to do about the Christians. Their refusal to pay allegiance to the imperial cult – indeed, to worship any of the gods – makes them a menace to society.”

“But their numbers are quite small, are they not?” said Plotina.

“One of my ministers estimates they account for five per cent of the population,” said Trajan.

“Respectfully, Caesar, I think that estimate is much too high, even in the Eastern cities where their numbers are concentrated,” said Hadrian. “The aggravation they cause is out of all proportion to their actual numbers. Most people see their flagrant atheism as a clear threat to the security of the Roman state, which has always depended on the favour of the gods. When a pious, law-abiding citizen – in Antioch, say – discovers that a Christian is living next door, that citizen is likely to demand that a magistrate do something about it.”

“And if the magistrate acts?”

“The Christians are arrested, incarcerated, and given a choice: recognize the emperor and the gods by the simple act of burning incense on an altar, or be executed.”

“And some of these fools actually choose to be executed?”

“These people are fanatics, Caesar.”

“What if the magistrate does not act?”

“People take the law into their own hands. Christians have been burned out of their homes and driven off, even stoned to death by angry neighbours. As you can imagine, that sort of thing causes a huge headache for the authorities in charge of keeping the peace.”

Trajan rubbed his nose thoughtfully. “But such incidents are rare, are they not? In my experience, whether one is in Antium or Antioch, most people try to get along with their neighbours and mind their own business, even if the neighbours are Christians.”

“And what of the legions?” said Hadrian.

“Surely a Christian soldier is a contradiction in terms,” said Plotina. “I thought these people were opposed to killing.”

“Nonetheless, there are reports of Christians being found among Caesar’s soldiers, where they greatly upset morale. A legionary who refuses to sacrifice to the gods before battle poses a clear danger to his comrades. No pious soldier of Roma wants to serve beside such people in combat.”

Trajan shook his head. “It seems to me that an official policy of aggressively seeking out and punishing this tiny cult would be a waste of resources, more trouble than it’s worth, likely to make people anxious and upset for no good reason. I certainly don’t want to reward these death-worshipping fanatics with the attention they crave. And I am determined not to follow the example of Domitian, who was ready to believe that anyone was a Christian if an informer told him so. Such an accusation became an easy way to blackmail or get rid of an enemy, which is one reason our estimate of the number of Christians may be inflated – there are more people accused of being Christian than there are Christians!”

Trajan waved to the secretary, who brought a stylus and wax tablet, and began to dictate. “Notes for my response to a query from a provincial governor in regard to the Christians: These people are not to be sought out. If brought before you and found guilty, they must be punished. But even to the last minute, if such a person should repent and consent to worship the gods, he should be pardoned. Anonymous accusations must play no role in any prosecution; such practices are a discarded relic of a previous time. The official policy regarding the Christians, in a nutshell, may be summed up thusly: ‘Ask not, tell not.’”

He turned to Hadrian. “There, what do you think of that?”

“Caesar is like a father who wishes to keep peace between his children, even the worst of them.”

Trajan was amused. “Speak freely, Little Greek! What do you really think?”

“I think that Caesar is perhaps tolerant to a fault. But that is the opinion of a man much younger and less experienced than Caesar.”

“Don’t rub it in!” Trajan laughed. “Erudite, pious, and clever is our Little Greek.”