Nothing united Camelot better than a good tournament.

At first Merlin had been uncertain about all the noise and the crowds flooding into the city; he had had to close his shutters to be able to concentrate on reading, or go up to the library, which he liked but which intimidated him a bit; but, when Gaius had explained to him that all of these visitors had come for a tournament – and one of the high points of the Camelot calendar – Merlin's interest had been at once piqued.

The contestants were put up in the castle itself, and were a common sight about the place over the next few days; Merlin was too young to recognise their actual authority – most were nobility and a few were royalty – but he did respect and admire the magnificent coats of arms that adorned their tunics, the variously coloured cloaks that billowed in the corridors and created a cloud of colour down in the courtyard. Their assistants were housed either with the servants, or in the town; and the inns of Camelot were stacked with spectators from surrounding counties and kingdoms. The place was full to bursting, and even walking down the street was a challenge worthy of its own tournament.

Merlin hadn't yet seen the arena, which was just outside the city walls, and which was scarcely used outside of such events as this. Therefore his eyes were wide as he and Gaius went to find a place in the stands: already people were beginning to fill the rows, adding a wonderful variety to the striking red wood; the circle of the arena itself was huge, as if they had wanted to race chariots in there; and the royal box was magnificent, a flurry of purple and red and gold that rivalled the spectacle to come. The contestants had not yet emerged from their tents, but there was a chattering coming from that general direction. More conversation began to arise variously from among the gathering crowds; shouts began to go up from opportunistic traders who had set up shop just at the entrance. One woman ruffled Merlin's hair and called him a darling and gave him a little cake for free. Gaius felt obliged to buy a cake for himself, but he didn't eat it; he wrapped it in a scrap of cloth and said that if Merlin was good he would be able to have it for dinner.

They managed to find a good place in the stands, as the people of the castle had a little area reserved just for them, by the sides of the royal box. Gaius began to chat with a couple of the other servants, who had shuffled in beside them. Merlin leaned over and kept a beady eye on the proceedings. He did not know much about what was going on, beyond the scraps of gossip he had caught over the past few weeks. He knew that this was one of the most thrilling tournaments in existence, owing to the talent and variety of the contestants. He knew that the King himself had in previous years participated as one of Camelot's champions, before an injury and his age had forced him to back down. And he knew by sight this year's favourite from the city: a certain Sir Leon, a young knight – scarcely an adult, in fact – who wasn't yet the best Camelot had ever seen, but who, with a few more years' experience, would be an extraordinary fighter, if the experts were to be believed.

There he was. Camelot's flag had just appeared over the entrance to the arena, borne by a servant, behind whom promenaded four knights: and at their head was the apparently indestructible Sir Leon, looking very sturdy in his shining armour and emblazoned tunic. The other kingdoms followed the hosts, as per usual, as the last of the spectators filed in, and as the vendors at the gates hurriedly packed up: they would parade around the ring a few times, so that everyone got a good look at the stakes. And, in the background, the musicians struck up a merry tune, trying to compete with the loud chatter and the cheers that went up from the crowd, when the champions passed their countrymen. Perhaps they were playing a tune; all Merlin could hear was the screech from a flute and the blasting of a rudimentary trumpet. Somehow that just made everything more thrilling.

And they returned to their tents, save for the first two contestants: Sir Leon, and a man whose name Merlin did not know but whose flag told them he was from Wessex. Gaius had leaned over to his neighbour to ask who this opponent was; Merlin did not catch the name, and called him The Enemy, for want of something better, and because he had felt a surge of patriotism rise up in him.

He watched Sir Leon and The Enemy stand opposite each other, and bow, first to each other, and then to King Uther, who was invisible to the audience in his box. Then they drew their swords, and ran at each other.

Merlin felt himself catch a breath: for a terrifying moment it had seemed as if they would kill each other instantly. Then he settled back and remembered that this was all just a game, a sport, a tournament, and furthermore a glorious one: and, as the crowd began to cheer on their favourite side, he found himself entirely caught up in it, and began to shout, in a high voice that could scarcely compete with those around him, Sir Le-on! Sir Le-on!

A few moments later he heard his chant repeated a couple of rows behind him: when he turned, he saw the friendly squire he had talked to at the dinner, who beamed down at him; and, a few places along, among the people of the lower town, Gwen and her father, who were also smiling in his direction, and who cast this chant into the arena and towards the entirety of Camelot.

Gwen's father's voice was loud and resonating, an advantage; soon everyone was cheering in this way for Leon, and clapping as well. Merlin turned his attention back to the fight. The knight in question lunged for his opponent – knocked him to the ground – everyone got ready to cheer, but The Enemy picked himself up and swirled out of the way of Leon's next blow, in a smattering of dust and sweat. Merlin thought for a moment that The Enemy would mimic Leon's tactic: but the latter dodged, danced across the arena, kept on his feet by a miracle of balance. Truly, Sir Leon was a glory to watch. He had been called indestructible: Merlin could well believe that, for he seemed to get himself out of the most impossible of scrapes. But, though his defence was finely-tuned, he had not yet had much opportunity to attack. That was about to change.

The Enemy, who had evidently not expected Sir Leon to withstand so many onslaughts, paused for a moment to catch his breath. A mistake. The people of Wessex, and their allies, audibly gasped, because in that moment their champion had brought about his downfall: Sir Leon ran at him, bowled him over, and, before Merlin had even registered what was going on, he lay on the ground with a sword at his heart, defeated.

Leon stood there a moment, his shoulders heaving; then he grinned, pulled off his helmet, waved at the crowd, acknowledged the king as gracefully as he had fought. The Enemy accepted his defeat and the handshake that his opponent offered him, as he stood painfully, covered in dust but nevertheless smiling. Merlin clapped and cheered more loudly than in his life before: the fight had exhilarated him. His mentor at his side looked a little disapproving at this loud display of excitement, but he was not serious, and Merlin saw a smile twitching at the corner of the physician's mouth.

'Having fun?' he asked of his little ward, when the noise had died down enough to hear himself think.

Merlin could only nod eagerly; his eyes were fixed on the outline of the tents beyond the gate, hoping to catch the first glimpse of the next competitors. To one side was a servant adjusting the scoreboard, which was covered with small copies of the flags that now fluttered over the gate. Wessex was not yet out, but they were one man down out of three, and leastways the first losers always seem the most disadvantaged. Inversely, the first victor was glorified, and Sir Leon paraded back to his tent in a flurry of cheers and clapping and screeches, and, as he walked past the stands, a hail of handkerchiefs from an overly eager group of young Camelot women.

The next two competitors were favourites among the crowd, given the sounds of it: or at least, the man from the Western Isles was. His black and yellow tunic had stood out in the castle, as he had walked proudly down the corridors, as if he had already won the tournament: and Merlin had glimpsed his shield before, though he couldn't quite remember where: it was a distinctive one, its red and green snake design seeming to clash with the colours of his standard, but with a beautiful intricacy that he had rather admired. But there was no time to admire pictures now: the attraction would be in his fighting, and apparently – or so the conversation around him told him – he was really rather good.

'Bet he isn't as good as Sir Leon,' Merlin commented in a low voice to Gaius.

'Oh, I doubt it,' said Gaius with a small smile.

His name was Valiant, but he had also earned the epithet Gallant during his (thus far short) time in Camelot, owing to his chivalry: and he certainly showed it now, in an almost exaggerated fashion, in his acknowledgement of the king followed by his opponent. He smiled widely around at the crowd, murmured something to the other man – it looked like good luck from here – and slid on his helmet. At his smile, a cheer had gone up, particularly from the ladies in the audience. But Merlin hadn't much liked the smile. He couldn't say why, though.

Then the fight began. Valiant was certainly a good fighter: but Merlin had been right, he didn't have half the grace or the art of Sir Leon. His tactics were violent and rather reckless: he battered his opponent, pushing him backwards, raining blows down on his shield so that he didn't have any chance to fight back. Remarkably, the opponent managed to stay upright for a long while, lashing out, but never landing any blows; skidding on the floor, but managing to keep his balance; flicking reassuring smiles towards the audience that didn't reach his eyes. Valiant's own eyes were burning, burning with a fire, almost angrily. Merlin supposed that that was what men felt when they fought. To him, fighting, even for fun, always seemed somewhat aggressive, and though he enjoyed watching it, he wasn't sure he wanted to get too near. And especially not to Knight Valiant.

At last the poor opponent fell to the floor; it seemed as if he had merely given up, and his legs buckled beneath him. Nobody could blame him. The fight had lasted for what seemed like a long while, and Valiant's attack had been particularly pernicious. Valiant, too, seemed exhausted for a moment, and knelt by his opponent, lowering his sword and his shield.

And that was when he saw it. Merlin, who was still watching Valiant's eyes in something akin to fear, caught a momentary glimpse of gold, a light he thought he knew. Then they regained their previous dark fiery tones; and Valiant, with a glance towards his fallen opponent, caught his breath and stood. Now his gallant persona was back: he smiled round at everyone, bowing modestly as the people cheered, bowing low to the king. But his opponent did not get up, and, seeing this, the servants at the gate ran into the arena and picked him up, carting him away to attend to him, see if he was wounded, or merely exhausted.

And Valiant also disappeared; the chatter of the crowds filled the interval before the next men arrived. But before they had even appeared in the arena, someone came running round the edge, leaned over the side, called out to Gaius that he was needed in the tents.

'Will you be all right here?' Gaius asked of Merlin.

Merlin hesitated, then nodded. The squire behind him offered to keep an eye on him. Gaius thanked the boy and left with the messenger: and Merlin's eyes followed him as he rounded the arena and disappeared from view.

As the exhilaration from this fight faded, Merlin suddenly found that he was trembling. In all the tumult he had almost forgotten what he had seen. Valiant's eyes had glowed. It hadn't been a trick of the light. He was certain of it. If he wasn't much mistaken – Valiant had done magic.

But what to do? What had he done? Had anyone else seen? Merlin scarcely dared mention it to anyone; if he was wrong, and Valiant was wrongly convicted – he would die. He couldn't do that to anyone. Accusing someone of magic was such a serious matter that Merlin didn't think he would ever be able to do it.

And yet – something had happened. A deep sense of foreboding had coursed through him when the man hadn't got up – when Gaius had been sent for. Something had happened. It probably had something to do with whatever Valiant had done. Had nobody else seen? Merlin cast a glance round the rest of the spectators. All of them had begun to cheer as the next competitors arrived in the arena; none of them looked as perplexed as he felt; anyway, few of them would have been able to see Valiant's eyes – Merlin was in the front row, and furthermore small, and had been at exactly the right level.

Should he tell someone?

Maybe he would, when he knew what had happened. Maybe he would tell Gaius, at least. The old physician would be angry with him if he didn't say what he knew.

He turned briefly, saw that the squire was clapping and cheering with the rest of them. And, though his thoughts were still a whirlwind within his mind, he cleared his face of all confusion, and tried to pretend for the moment that nothing had happened, as he was so used to doing.