We detoured to call on Sextus Silanus. We had to pass on the tragic news of his uncle’s death. Petronius would explain the circumstances. My role would be to watch this conversation unobserved, judging the nephew’s reaction. He had benefited financially from the death. Some investigators would pin the murder straight on him. When motive gives you a quick way to clear up a case, who needs facts?

Silanus came to the shop door, saw our cavalcade, recognised me, and expected the worst. Petronius Longus always looked as if he had a grim purpose. His bearing and sombre face gave away the reason for our visit. The numbers in our group also indicated that Modestus and his fate were at last of official concern.

We had the ox cart, containing some of us and our baggage. On dilapidated mules were a couple of Petro’s men, all he could safely scrounge from duty: Auctus looked too fragile to fight fires but he had been in the cohort for years and everyone accepted him; he was riding Basiliscus, a skeletal beast with a bent ear and bad breath. Ampliatus had an eye missing and rode a brindled, knock-kneed mule called Corex who kept running away. Although the vigiles are ex-slaves, most were not quite so off-putting; these were the only two men who would volunteer for our destination.

Petronius had left Fusculus behind in charge, though we wished we could have had that steady fellow with us. Somebody had to do Marcus Rubella’s vital job; at least, that would be Rubella’s view.

In charge of the cart, Petro’s brother had a similar relaxed driving style, holding the reins in one hand loosely and letting the ox make his own pace. Otherwise there was little resemblance between them. Maybe there had been a frisky lupin-seller in the neighbourhood just before Rectus was born, though I did not risk the joke. Rectus was older, shorter, of squashy shape and slumped posture, an unsociable fellow who seemed hard to like. They had had very little to do with one another for years. I was sure Petro once told me his brother was a bit of a fixer and mixer, though he gave no sign of it. Perhaps age or the marsh fever had slowed him down. When anyone asked Rectus about the fever (which we did frequently, because we were all petrified), he just grunted; if pushed further, he let out a sardonic laugh and turned away. I decided not to discuss him with Petronius. Let him volunteer a comment if he wanted to.