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."