I DON'T DO EVIL when I'm not on duty, just as prostitutes tend not to have sex on their days off. My ideal off-shift day starts with a hot bath and the scent of black tea, followed by an hour on my balcony with a good book; then a stroll through the busy streets to view an art exhibition, hear a sermon or a philosophical debate, or simply admire the mosaics in the Blue Temple; lunch on the terrace beside the river with a friend or two (not work colleagues); an afternoon with no plans or commitments, so I can be totally spontaneous; a light supper; then to the theatre or the opera, and so to bed.

A really bad off-shift day starts before sunrise, with an urgent message to say that something's come up, it's so delicate and important that the other shift can't handle it, and I'm to report to some hick town thirty miles away, dressed, shaved, and ready for business in twenty minutes. You may argue that I get days like that because I'm so good at what I do, better than anyone else in the department, so really it's the nearest our organisation can get to a pat on the back and a well-done. Maybe. It doesn't make it any less annoying when it happens.

You don't have to enjoy your work to be good at it. Frankly, I don't like what I do. It offends me. But I'm the best in the business.

* * *

"Quite a catch," the briefing officer told me. "We need more intellectuals."

That was news to me. "Do we? Why?"

"To maintain the balance. And to demonstrate the perils of intellectual curiosity taken to excess."

"Is that possible?" I asked, but he just grinned.

"That's the line to take," he said. "And you say it like you mean it. I guess that's what makes you such a star."

Of course, I have no input into policy. "From what the brief says he doesn't need any persuading," I said. "Do you really need me for this? Surely it's just a case of witnessing a signature and writing out a receipt."

"You were asked for. Specifically. By name."

I frowned. "By Divisional Command?"

"By the customer."

I don't like it when they call them that. "Are you sure?"

"By name," he repeated. "A well-informed man, evidently."

"Nobody's heard of me."

"He has."

I changed my mind about the assignment. I've remained obscure and pseudonymous all this time for a reason. "And he's all ready to sign?"

"We didn't approach him. He came to us."

Oh dear. "Has it occurred to you," I said, "that the whole thing could be a setup? A trick? Entrapment?"

He smiled. "Yes," he said. "Take care, now. Have a nice day."

* * *

Oh dear cubed.

Entrapment is not unknown in my line of work. As witness Fortunatus of Perimadeia, a great sage who was active about four hundred years ago. Fortunatus conjured a demon, trapped him in a bottle, and distilled him into raw energy. Likewise the stories about Tertullian, who challenged the Prince of Darkness to a logic contest and won. Both apocryphal, needless to say, but stories like that give people ideas. What more prestigious scalp to nail to your tent-post, after all, than one of us?

I read the brief again. I insist on having one, written on real parchment with real ink; physical, material. It's regarded as an eccentricity, but because of my outstanding record I'm allowed to have them. I find that reading words with mortal eyes gets me into the right mind-set for dealing with human beings. Attention to detail, you see. Proverbially I'm in it, so why not?

* * *

The appointment wasn't till two o'clock, which gave me the morning. I decided to make the most of it. I walked up the Catiline Way to see the spring flowers in the Victory Gardens, then spent a delightful hour or so at the Emilian House, where a very promising young artist sponsored by the duchess had put on a show; stand-alone icons, diptychs and triptychs, very classical but with an elusive hint of originality; above all, genuine feeling, such as only comes through genuine faith. The artist was there, a shy, unassuming young man with long, dark hair woven into knots. I commissioned an icon from him for forty nomismata — the Invincible Sun and military saints standing facing, holding labarum and globus cruciger. The poor boy looked stunned when I suggested the price, but then it's the duty of those who are in a position to do so to support the fine arts.

I still had an hour to kill, so I wandered down into the Tanner's Quarter, sharp left at the Buttermarket cross into Bookbinders' Street; nosed around the booksellers' stalls, picked up a few early editions. "You wouldn't happen to have," I asked, "the latest Saloninus?"

The man looked at me. "What do you mean, latest? He hasn't written anything for years."

"Ah. What's his most recent?"

The man shrugged. "Probably the Institutes. I haven't got that one," he added. "We don't get much call for that sort of thing." He looked at me, making a professional assessment. "I've got a very nice late edition of the Perfumed Garden of Experience."

"With pictures?"

"Of course with pictures."

I didn't ask the price. A book of no interest whatsoever to me, naturally, except in a broad professional sense; but the late editions are very rare, and the quality of the artwork is actually very good, regardless of the subject matter. Money changed hands; then I said, "So what Saloninus have you got?"

"Hold on, let's see. I've got two old Moral Dialogues and — oh, you'll like this. Forgot I had it. Limited numbered edition, best white vellum, illuminated capitals, the whole nine yards."

"Sounds good. Which book?"

"What? Oh, right." He squinted at the tiny letters on the brass tube. "Beyond Good and Evil."

"Perfect," I said. "I'll have it."

* * *

At two o'clock precisely by the Temple bell (it's five minutes fast, in fact, but since all the time in the Empire is officially taken from it, who gives a damn?) I turned down a narrow alley, found a small door in a brick wall, and knocked. No answer. I counted to ten, then gently rearranged the position of the wards inside the lock. "Hello," I called out, and went through into a charming little knot-garden, with diamond-shaped herb beds bordered with box and lavender. In the middle was a sundial; beside it was a handsome carved rosewood chair; in the chair was an old man, sleeping.

I stood over him and carefully nudged his brain back to consciousness. He looked up at me and blinked. "Who the hell are you?"

I smiled. "You wanted to see me."

"Oh." He frowned. "You're him, then."

"Yes."

"You're not —" He stopped. I grinned. "I expect they all say that."

"Most of them."

He stood up. It cost him some effort and pain. I eased the pain slightly; not enough to be obvious. "You might as well come inside," he said.

His study opened onto the garden. I imagine he liked to sit with the doors open, in the spring and summer. It was a stereotypical scholar's room; books and papers everywhere, walls floor-to-ceiling with bookshelves; an ornately carved oak desk with a sort of ebony throne behind it, a low three-legged stool on the other side. I got the stool, naturally. I made myself comfortable. I can do that, just by shortening a few small bones in my...