As we stood in the hot room that evening, we faced decision time. During the day, I had done most of the heavy work. I was exhausted, yet I still rejected Pa's offer to scrape a strigil down my back. I made a rough job of cleaning off the oil myself. Pa favoured a concoction of what seemed to be crushed iris roots. Incongruous. And on that hot sultry night, nowhere near strong enough to mask the other smell. "Rhea right." I glanced down at the floor. "Something's rotting in your hypocaust."

"No, no; trust me!" Pa used the voice he kept for assuring idiots that some piece of Campanian fakery could be 'school of Lysippus', if looked at in the right light. "I told Gloccus to omit the hypocaust from this room. His quotation was outrageous for under floor work. I worked out some figures myself, and with that kind of area to heat, I was going to be spending four times as much on fuel…" He tapered off.

I eased my foot against the wide instep strap of a bath shoe. Helena's original scheme had involved properly heating the whole warm suite. Once she admitted what she was up to here, I had seen the plans. "What have you done then?"

"Just wall flues."

"You'll regret it, you cheapskate. You're on high ground. You'll find it chilly round your rude bits in December."

"Give over. I work right by the Baths of Agrippa." Entrance was free. Pa would love that. "I won't need to use this place except in high summer."

I stretched slowly, trying to ease the stiffness in my lower back. "Is the floor solid? Or had they already dug out a hypocaust when you decided against it?"

"Well, the lads had made a start. I told them to floor over the cavity and block off any links to the other rooms."