Then bringing her head would not be that troublesome for Tisamenos. It was just a matter of finding her old lair and then the skull of the Gorgon – it must be a skull by now, surely? Then all he would need would be a sword, and maybe a dagger, in case of bears or wolves. A couple of torches, too, to light the cave.

And was it true that the Gorgons turned people into stone? Surely that was just a legend. But just in case he would need a shield, so that he could look into it. And a sack. He shuddered inwardly at the thought of the sack. To put her head in.

‘Where was her lair?’ he said, offhandedly.

Agatha regarded him unblinkingly for a long time. Then she made the sign to ward off evil, and said, ‘They used to say in the foothills of the mountains. But – oh I see your grandfather Agamemnon in you!’

A burst of pride filled Tisamenos’s chest. But it faded as Agatha continued. ‘Be careful, my sweeting. You are not made for this terrible world.’

Orestes that afternoon was engaged in watching the first races. The athletes were preparing as Tisamenos went by the palaestra, oiling themselves and flexing their muscles. He kept to the shadows, a cloak wrapped around his head. He felt a pang of anger when he saw Erigone by Orestes’s side, a young nurse carrying the new baby. Orestes, who loved the games, was clearly enjoying himself. He wouldn’t notice if Tisamenos was missing.

Tisamenos stalked through the streets, wondering at every turn where the headquarters of the Swallows were. Soon he went past the last few poor huts where goatherds and swineherds lived. A pig grunted, then he was out through the Lion Gate, and hurrying down the winding road to the plain below, and the forests.

He had been into the forests before, out hunting, but usually with a large retinue. His father on the finest horse, surrounded by the boasting huntsmen. His own mount, smaller but sometimes quicker. But he’d never been on his own.

As soon as he passed beneath the trees, he felt a chill. Every branch seemed to point itself into a finger, warning him. Every rustle, every creak, made him look over his shoulder.

Steadily, though, he made his way northwards, keeping to the rough deer track that the hunters used.

Eventually he came to the foothills. There was only one cave that he could see, and he decided to investigate. There were no goats, or any other signs of life. The mouth of the cave was low to the ground, under a lip of rock, and he examined it for a long while. It was only when a swallow swooped across the space in front of him that he steeled himself. He lit one torch, and went inside.