No tents were pitched, so that the perimeter was as small as possible while still enclosing all the men and the animals. Crispinus detailed double the normal number of men to stand guard, and told the rest to sleep rolled up in their cloaks and with their arms to hand. At least it was dry so that fires could be lit and a hot meal prepared. Oddly, for all the rumours of severed heads and curses, the mood was brighter than the previous night. Ferox ate quickly and slept during the last hours of daylight. He had given the scroll to Philo to decipher and the task cheered the young slave, making him feel useful and important. After a moment’s glance he told his master that the language was a mix of Greek, Aramaic, Old Hebrew and Egyptian, but that much of it was gibberish or secret words of power. Yet one theme was repeated in all the tongues. ‘Blood of king, blood of queen, blood of power and blood of woe,’ it said again and again. ‘It will take longer to work it all out,’ the slave said. ‘I’ll keep at it.’

‘Good lad,’ Ferox told him. ‘It may be important.’

*

Halfway through the first watch Ferox slipped over the wall beside the stream. His face was smeared with ash so that his skin did not shine. He wore his boots and trousers but no tunic and was glad of the heavy hooded cloak because the air was chill. His only weapon was his army-issue dagger, unsheathed and tucked into the back of the simple rope belt he wore. Vindex had wanted to come, but the Brigantian was not used to this sort of work, and Ferox was happier on his own. He did not tell anyone else of his plan, including Crispinus and the other officers. If nothing happened then they would be none the wiser.

At first it was easier than expected. A stallion, one of many ridden by the ala Petriana, sniffed a mare on heat and began to whinny and pull at the stake to which he was tethered. Men gathered, there was shouting, and the guards on the wall by the stream turned to see, giving him all the time in the world to vault the rampart, jump to the far bank of the stream, run ten paces and then fall flat and lie still. Lying still was a big part of the game, and that was why the elders taught Silurian boys to love silence and stillness. Covered in the long cloak he would be hard to see. He waited until he was sure that no one had spotted him, then made himself wait even longer before he began to crawl slowly forward, wondered why whenever a man did this it took him straight over a cowpat, and then stopped, watching and listening.