I moved on, looking for the street where Calpurnia had told me I would find Hieronymus's apartment.

Years ago, when I lived in a ramshackle house on the Esquiline Hill above the Subura, I had walked through this neighborhood almost every day. I had known its meandering alleys like the veins on the back of my hand. Nowadays I visited the Subura less often, and much had changed over the years. The tall, crowded tenements, some of them soaring to six stories, were so cheaply constructed that they frequently collapsed and almost as frequently burned down. New buildings were quickly thrown up to take their place. Entire streets had become unrecognizable to me, and for a while I became lost.

Then, in the blink of an eye, I found myself in front of the very building I was searching for. It was unmistakable. "Brandnew and six stories tall," Calpurnia had told me, "with a fresh yellow wash on the walls, a pubic fountain at the corner, and an eatery on the ground floor." She owned the building. A part of her arrangement with Hieronymus had been to supply him with free lodging.

Calpurnia had told me I would find a slave posted in the tiny vestibule. He was there partly for the security of the tenants but also to make sure they didn't start cooking fires in their rooms or carry on any business that was too dangerous or too illegal. I encountered an unshaven young man so scruffily dressed that he might have been a beggar who had wandered in off the street, but the suspicious look he gave me was definitely that of a watchman.

"You must be Agapios," I said. "My name is Gordianus. Your mistress sent me." For proof I showed him a bit of sealing wax into which Calpurnia had pressed her signet ring. For a symbol she used the profile of King Numa, with his flowing beard and priest's mantle. The Calpurnii could trace their descent from Calpus; he was one of the four sons of pious King Numa, who lived more than hundred years ago and was the founder of many religious rites and priesthoods.

He bowed obsequiously. "What can I do for you, citizen?"

"You can show me to the room where Hieronymus of Massilia lived."

The young slave caught my use of the past tense and shot me a curious look, but he said nothing. He turned and motioned for me to follow him up the stairs.

Usually the choicest apartments in such tenements are located in the middle floors, high enough to escape the noise and odors of the street but not so high that climbing the stairs becomes an onerous challenge, or jumping from a window in case of fire means certain death. I had expected to find Hieronymus's apartment on the second floor up, or perhaps the third, but the sprightly watchman bounded up one flight of stairs after another. I found myself huffing and puffing and called to him to slow down, but he had disappeared from sight.

I followed at my own pace and eventually caught up with him on a landing. He was miming boredom by examining his cuticles.

"Hieronymus lived all the way up here?" I said. "I should have thought-"

"Not on this floor. One more flight up."

"What!"

"You have to take this final flight of steps, over here."

Why had Hieronymus left my home for such a place? This tenement was not as squalid as some, but was it really an improvement on the comfortable quarters I had provided for him?

The last flight of stairs delivered us not, as before, to a landing with dark hallways leading to numerous apartments but to a single door with an open skylight above. Under the bright sunshine, the watchman produced an iron key and opened the door.

The room was sparsely furnished, but the rugs and chairs were of good quality. The space was brightly lit by unshuttered windows on either side. A doorway appeared to lead to another room. Another doorway opened onto a terrace that entirely encircled the apartment. I stepped outside.

"A rooftop apartment?" I said.

"The only one. The tenant had it all to himself."

Hieronymus had done well for himself, after all. The space and seclusion would have suited him, and the vista would have reminded him of his pampered days in Massilia. This was one of the tallest buildings in the Subura, and the view was virtually unimpeded in all directions. Beyond the Forum there was an excellent view of the Capitoline Hill with its crown of magnificent temples and monumental statues.

I leaned forward, peered over the parapet, and felt a bit dizzy, gazing down at the tiny figures in the street below.

"How well did you know him?" I said.

"The tenant? Not at all. He kept to himself."

We stepped back into the apartment. "Did he have visitors?"

"Never. You speak of him in the past tense. Is the tenant-?"

"You can go now, Agapios. Leave the key with me, so that I can lock the door as I leave. In fact, I'll keep the key."

"But tenants always leave their key with me when they go out. I don't have another."

"Good."

"But the mistress-"

"I have authority from Calpurnia. I showed you the seal."

"So you did," said the slave, cocking an eyebrow. "All very mysterious!" He paused in the doorway and turned back. "You know, for a graybeard who can barely manage the stairs, you're not bad looking." He skipped lithely down the steps and vanished.

I stood, confounded for a moment. It had been quite some time since a young slave of either gender had flirted with me. I blinked and caught my reflection in the polished square of copper hung on the wall beside the doorway. Hieronymus must have used it for checking his appearance before leaving his rooms. The full lips set into a frown, the knitted brow, the flattened nose (a boxer's nose, Bethesda called it) all projected a stern countenance. The silver-streaked hair and beard were kept short and neatly trimmed; that was my daughter, Diana's, doing. There was perhaps a certain gentleness about the eyes, a suggestion of the callow youth I once had been, a lifetime ago.

I watched a trickle of sweat run down my forehead onto my nose. All the heat of the building rose to these rooms, which were baked by the sun as well. I grunted and wiped the sweat away, then shrugged at the figure in the mirror and set about exploring Hieronymus's lair.

I walked from room to room and searched the usual places. I lifted the rugs. I checked the chairs for false bottoms and rapped on the legs to see if they might be hollow. I rummaged though the trunk that contained his clothing. There were a few cups and jars and other containers; they held only wine or olive oil for the lamps. I examined the narrow bed, the straw mattress, the coverlets and the cushions. He kept his valuables in a little box under the bed. I found some coins and a few trinkets, but not much else of value.

Hieronymus had kept a small collection of books. The rolled-up scrolls were neatly inserted into a tall pigeonhole case against one wall. Most of the scrolls were identified by little tags with titles and volume numbers written on them: Eirenaios's History of Massilia, Fabius Pictor's History of Rome, the Epigrams of Appius Claudius the Blind, and so on. Perusing the bookcase from top to bottom, I came upon a whole row of scrolls that had come from my own library, including a rare copy of Manius Calpurnius's Life of King Numa. Cicero had given it to me many years ago. I couldn't remember ever lending it to Hieronymus. When he vacated my house, he must have borrowed it-if "borrow" was the correct word.

Feeling a bit peeved, I pulled the scroll from its pigeonhole and unrolled it, wanting to check its condition. The scroll was intact, but several loose pieces of parchment had been rolled up inside it. I removed these extraneous pages and saw that they were covered with writing in Hieronymus's hand. I had only to scan a few lines to realize that I had found what appeared to be a private journal, kept hidden inside the scroll of Numa.