The Spartans were terrifying. He found himself utterly still, frozen as more and more looked at him. He did not see the spear thrown, twenty paces along the line. It flew hard and fast, taking him between helmet and breastplate, in the hollow of his collarbone. A dozen others flew wide of him, but it only took one. Mardonius fell, slipping to the ground with his throat ruined. His eyes were wide in horror and panic as he scrambled to his feet, heaving for breath with one hand clutching his neck. He could feel his pulses beating and he couldn’t speak. He turned as the Immortals came jingling through their own people, moving faster and faster as they sighted red cloaks. Mardonius gave thanks. He stood with one hand on his horse’s saddle-pommel and the other keeping him alive.

The Spartans knew the white-coated Immortals and what they meant. Somehow, they turned the vast square to face the ranks charging them. As they came together, Mardonius felt hope slowly shrivel and die. The Spartans blocked and stabbed with their spears, like a dance. They shifted subtly away from blows, so that the strength of better men was wasted. They were hard to hit, but they knew their own tools. They tore through the Immortals just as fast as the Persians could come on. There was barely time for each rank of white-coated men to understand the threat before they were cut and speared and knocked down.

When the spears broke, the Spartans drew swords and the killing was worse. They did not seem to tire as ordinary men did. Mardonius watched a great churn of his Immortals as rank after rank was slaughtered. His entire army spun around them and yet they could not break the Spartan square. There was fighting off somewhere else, but this was the heart of the battle, as he had always known it would be.

He had not brought enough men. Mardonius watched Hydarnes himself attempt to smash their line with his horse. The general was spitted on thrown spears, with two more grounded and held up for the horse to run onto. The animal screamed, or Hydarnes did, Mardonius was not sure. He watched and waited for an age, while his army milled and panicked and fought and ran around him. One by one, senior officers died. When Mardonius understood they could not break the Spartans, that the day would be theirs, when he could not stand the despair a moment longer, he pulled his hand away from the flesh of his throat and slid to the ground.