Cato knew that there was no sense in provoking any disturbance. He backed off a few paces and then turned and walked back towards the Boarium. Then it occurred to him that there was still something useful that he could discover and he broke into a run. He pushed his legs hard, looking for the man in the yellow cloak and his two bodyguards. There was no sign of his easily distinguishable cloak on the length of the wharf, and Cato ran on into the Boarium. Even though the market was not filled with its usual dense press of bodies, there were enough people to obscure Cato’s view. He pulled himself up on to the pediment of a statue of Neptune and hung on to the shaft of the trident as his gaze swept over the market. Then he saw the yellow tunic, on the far side, close to the hall of the grain traders.

‘Oi! You! Get off!’

Cato looked round and saw a soldier from one of the urban cohorts striding towards him. Cato clambered down and made to leave the spot but the soldier blocked his path.

‘What do you think you’re doing?’

‘Looking for a friend.’

‘Trying to cause trouble more like.’ The soldier growled and slapped the side of Cato’s head, making it ring. Cato blinked as he staggered to one side.

‘Acer!’ a voice cut through the air. ‘That’s enough!’

An instant later an optio stepped up and glared at the soldier. ‘We’re here to keep the peace, you bloody fool. Not to start another fucking riot.’ He turned to Cato. ‘You! Get on your way!’

Cato nodded, and staggered off through the market, heading towards the halls of the merchant guilds on the other side of the Boarium. People who had witnessed the confrontation stared warily after him, as if he carried some kind of frightening mark. It was a sign of the nervous tension that still hung over the city. No one wanted to be associated with any man who fell foul of the military. Cato’s head quickly cleared and he slowed to a steady pace as he crossed the market. He could no longer see any sign of the yellow cloak outside the hall of the grain merchants and feared that he had lost his man. As he reached the portico, topped by a pediment and statue depicting Ceres holding a thick sheaf of wheat, Cato paused and looked round. There was no sign of the bald man, so he continued inside.