The food turned out to be a patty of ground pork, stuffed in the middle of a slab of bread. The meat was well-cooked and flavoured with onions. Brigonius took a bite. ‘Might be better if it was beef.’

Karus said around a mouthful, ‘Oh, Romans don’t much like beef. Or mutton. Barbarian foods, they say.’

‘The soldiers at Vindolanda eat plenty of it.’

‘They’re probably all provincials themselves.’

Already Brigonius had finished his meal. ‘Is that it?’

‘I’ll buy you more later. Come on, let’s go to the forum and do some shopping.’ Lepidina took his hand - then, judiciously, Karus’s too - and they walked along the street.

The roads were paved, with gutters running down either side; the stonework was good, Brigonius noted. Along with the people animals thronged the streets - chickens, pigs, and many dogs. This was still a town for farmers. Most of the buildings were wattle and daub, like Karus’s apartment building, though one or two of the grander houses were built in stone. Most buildings were one-storey private houses, but some had their fronts opened out, like Karus’s restaurant, to reveal workshops where pottery was thrown, iron worked, glass poured, cloth woven.

Some of the images on the walls were there to show you what kind of workshop or store this was: cartoon potters turned their wheels, women displayed gaudy jewellery, and the taverns were marked by fat, merry drinkers. Even the brothels had their insignia, stick figures in remarkably inventive postures that Brigonius tried not to stare at. The lettering on the walls sometimes told you who lived here or what they did. Some of it, rougher carvings, was more casual, prayers, insults, curses. And some of it, lauding the Reds, Blues and Yellows, baffled Brigonius altogether. Karus said it was to do with support of the main teams of charioteers in the races. The various factions worshipped their heroes and loathed each other, and rioted on race nights.

Outside one store stood a large pot into which a burly man was noisily pissing; steam rose up from the pot’s neck.

Karus watched Brigonius’s expression with amusement. ‘This is a fuller’s; he will use the urine he collects from passers-by to fix his dye. I don’t cook in my apartment, and neither do I piss.’

Brigonius grunted, unimpressed. ‘And who collects your shit?’

Karus grinned. ‘Funny you should ask that.’

They came to a locked door fronting an enclosed hall. Karus produced a low-denomination coin and dropped it into a slot. He pulled levers on the lock mechanism until the coin was swallowed up, and with a satisfying clunk the lock came free.