‘Thank you, strategos,’ Eurybiades snapped.

It was a clear dismissal and Xanthippus sat. He had spent a day in fascinated experiment, just seeing what worked. He had come away with his blood seething in him, filled with excitement. Yet he knew Themistocles needed the Spartan, not just for his ships, but for the army his city could put in the field. Accordingly, Xanthippus bit his tongue and listened.

‘I have made my position clear – and you have spoken to counter it,’ Eurybiades said. ‘This is, no doubt, how the Assembly of Athens makes its decisions, yes?’

There was a bitter note in that, almost a sneer. Xanthippus waited, wondering where he was going. Eurybiades suddenly shook his head, as if he had weighed what he had heard and still could hardly believe it. To Xanthippus’ surprise, the Spartan began to pace back and forth. Even Themistocles settled back to hear.

‘On the field of battle,’ Eurybiades said, ‘Sparta has no need of counsel. Ours is a craft honed over centuries of study and labour. We have no equals. And yet …’

The Spartan took two quick short breaths, as if he was about to leap off something high.

‘And yet …’ he repeated, ‘at sea, our Spartan crews depend on the simplest of tactics. We draw close and board, overwhelming any enemy. The ship is a mere transport. The ram is for the rare occasion when an enemy hull has to be sunk, perhaps, or if they present their flank in an attempt to escape.’

He paused again and rubbed his chin. Not a man moved. It felt as if they were present at a birth, or some titanic struggle.

‘What I saw today seemed chaotic at times – a madness of ships, all rushing here and there without pattern. Yet what you describe has an obvious advantage. Three trained men will always beat one; two with less certainty. One against one, equally matched, goes on until both are exhausted. If the same can be said of our ships, bringing rams to bear, it should be … explored. I withdraw my objection, on all counts but one.’

Xanthippus felt his slowly spreading grin freeze on his face. Eurybiades turned to him.

‘What is the signal for withdrawal, this kyklos formation?’

‘Navarch, I thought it might be a black banner, but I have not practised it with the crews.’

‘And you will not. There will be no withdrawal, no retreat while I command the fleet. That is the limit of my authority.’ He glanced at Themistocles, who nodded, giving him the point. ‘That is what I say the limit is. Is that understood?’

Xanthippus felt Themistocles turn to stare at him, but he was not a fool. He bowed his head.

‘Of course, navarch.’

‘Very well. I will join your ship for tomorrow, to observe the signals and formations.’

Xanthippus smiled rather tightly as he agreed. The Spartan was trying, at least. Trying to overcome the stubbornness of his home city, the centuries of certainty that meant nothing at all at sea. Unfortunately, it seemed Eurybiades would be watching his every move from then on. Xanthippus shrugged off the worries that threatened to undermine him. He was an Athenian. He would just out-think the bastard.