Alaster Karo stared at the Space Marine, suspecting this was a mistake.

Alaster was stood on the polished floor of the gymnasium. Around him, people sat and watched on the benches at the back. The room was quiet, tense with indrawn breaths and eyes trained on the two figures stood on the floor. None of the spectators wanted to miss any detail of this scene. Nothing like this had happened in years. Behind the benches, sunbeams slanted in through the high windows. Dust motes glimmered in the lemon-tinted light of the Octalian afternoon.

Quite clearly, Alaster heard someone say, 'Is the kid mad?' Someone else shushed them. There was a faint thud and a rustle as some item was dropped on the back row.

'Are you sure?' asked the Space Marine.

Alaster looked up at the warrior. The marine was dressed in the blue-black and grey-trimmed armour of the Storm Ravens. He towered over the nervous teenager. In a weird, analytical flash, Alaster noted that you only got a true sense of the scale of marines until you saw one from close up. It was all well and good reading that they usually top seven feet and all the rest of it, but words on a page just didn't have the same impact. To make eye contact – he hoped – with the red-tinted lenses in the marine's helmet, Alaster's neck was craned. It wasn't comfortable.

Not trusting himself to speak again, Alaster merely nodded.

The marine turned to one side. He was looking at the party stood at the far end of the hall; two more marines, the school principal and several miscellaneous hangers-on. 'With your permission, Brother-Captain,' the marine said, 'I think it would be fair to even the odds a little.'

The captain was overseeing the Selection Games today. He had arrived with his escort of Astartes warriors just over two hours ago. The Selection was already underway and had been for several days. There were a lot of candidates to get through and the first stages were simple. The medicals and the races and the team games hardly merited Chapter attention, after all. Even at this stage, surprises were rare. The Marines' brief visit was just a formality, a polite gesture toward the citizens of Delta Octalis.

But then someone had done something unexpected.

Alaster swallowed. That someone had been him and he could hardly believe what he'd just done. He looked up at the enormous Space Marine. Alaster wondered what had possessed him – this really was madness!

'War is rarely fair, Brother Thaddeus,' the captain remarked. Every eye in the room focused on the Storm Raven commander. His presence was imposing; even just those few words had the audience riveted. The captain – the only Space Marine not wearing his helmet – looked at Alaster. Even from this distance, Alaster knew he was being scrutinised closely. The captain, Alaster noticed, had a wide scar running down his face. It just missed his left eye. 'Still, it's been years since anyone's used the Right.'

The so-called 'Right', of course, was the right of a selectee to challenge a marine to single combat. It was rarely invoked; when Alaster had announced his intention, many people in the room had no idea what he was doing.

The captain nodded to himself. 'I suppose that justifies throwing a bone. Toss him your knife, Brother.'

'Yes my Lord.' The marine – Thaddeus - reached down to his belt and unsheathed his combat knife. Alaster stared at it – it was the longest 'knife' he had ever seen. To anyone normal, it would be more of a shortsword. It had wicked serrations on its blade and an ugly, shiny and curved tip. Alaster dreaded to think what that would do to flesh.

The Storm Raven held it up so the audience could see it. The sunlight flashed along the blade. There was an audible in-drawing of breath.

The marine tossed it, almost negligently, toward Alaster. Alaster saw it spin toward him, turning end over end in the afternoon sunlight. It landed with a clatter at his feet, skidding almost to his boot. Carefully, gingerly, Alaster picked it up, gripping the hilt. He was amazed that his hand wasn't shaking – he could feel the building fear in the pit of his stomach. What had he been thinking?

Delta Octalis was the homeworld of the Storm Ravens Chapter. Alaster had known this almost from birth, like any other citizen of Octalis. He had been aware that after his fifteenth birthday he would be tested, like everyone else. The Selection was important. It decided everything – what jobs you could do, how many children you were allowed, how many votes you'd have. For a small number of male selectees, it would also choose them for training as Storm Ravens. That was its real purpose, of course, for all that the four billion other Octalians had co-opted the Selection for their own purposes.

Alaster had always known he would end up in this room one day. He had never imagined it would be like this. He clutched the knife before him, as if it were a shield.

Brother Thaddeus regarded Alaster again. 'Are you ready?'

Alaster nodded slowly, tensing. 'Whenever you are.'

Thaddeus sprang at him. The crowd gasped. Alaster ducked to the side.

The marine would have taken him there and then, but Alaster had been subconsciously readying himself for a leap. His muscles had begun unwinding even before Thaddeus began moving. Even then, it was close.

Thaddeus spun round. His fist slammed the air. Alaster felt the wind of its passage stir his hair. He had jerked his head, not an instant too soon-

The marine's other hand grabbed his shirt. Alaster's feet left the floor. His eyes locked onto the marine's right shoulder pad, seeing the insignia of the lightning-bearing black raven, wings outstretched against the blue background. His eyes tracked past the grey trim bordering the shoulder pad. He noticed it lift up and back, as the fist below it bunched.

'You can concede,' he heard Thaddeus growl.

An idea formed in Alaster's head. He had to distract the marine – just for a moment. He stared straight into the malevolent red eye-lenses, above the angry growl of helmet's rebreather. Alaster smiled, slowly and deliberately.

'Don't worry,' he said loudly, 'if you want to back out, that's fine. If it's too much for you…'

The marine roared something at him, angered by Alaster's words. Alaster didn't listen. While the marine bellowed, he swung his feet up and slammed them into the marine's breastplate.

Startled, the marine twitched – just a little.

In one fluid movement, Alaster jerked the combat knife up, tearing through the taught fabric of the shirt collar. It ripped loudly.

Suddenly free, he dropped to the ground. The crowd cheered and cried out and shouted in surprise and amazement.

Alaster hit the floor. He grunted as his hip collided with the surface. That hurt! He quickly rolled to one side and jumped to his feet. He was now twelve feet away from the Space Marine. Thaddeus was still holding the torn remains of the shirt. Alaster's bare chest rose and fell hard as he gasped for breath. His hip hurt and his legs ached from all the sudden moves.

Thaddeus dropped the torn rag to the ground. He kicked it away. 'The runt has some fight in him,' the Raven remarked. 'Who would have known?'

Some people in the audience laughed; Alaster felt his ears burning.

Thaddeus feinted; Alaster leapt backward. He heard the Space Marine laugh – it was not a welcome sound. For a moment, nothing happened, then the marine feinted toward Alaster. Alaster hesitated – and Thadeus broke into a run.

Acting on instinct, Alaster dived toward him. Hitting the ground, he rolled below the marine's fist. A leg swung out to kick at him. The sole of the boot actually clipped Alaster's nose. It hurt.

Alaster came to his feet, facing Thaddeus. With dismay, he realised his manoeuvre had only switched their former positions – nothing else. He was sore from his exertions, his hip ached and he was breathing hard. The Space Marine, meanwhile, looked as frightening and unruffled as ever. Alaster knew he couldn't keep this up much longer.

The marine closed his fist; Alaster noted the gauntlet had studs along the back of the hand. Built-in knuckledusters. A punch from that was going to hurt.

Alaster swallowed. He risked a quick glance at the clock on the wall. One minute – they'd been sparing barely two minutes. Maybe it was time to call it in. The rules of the Right were simple – for every thirty seconds you stayed in play, you advanced a level on the Selection. Beforehand, Alaster had been rated at a level two – as long as he didn't concede, this minute could take him to a level six. Another thirty seconds and he could rate a seven. His parents were both fives; he knew that getting to seven would make a real difference to the rest of his life. Even if it meant getting his lights punched out, it would be worth it.

His eyes gravitated back to Thaddeus's fist. The marine was about to strike, he could see it. Something about Thaddeus's manner suggested this time it was serious. Before, that had just been play. Let the daft kid have his moment in the sun. But that manoeuvre with the shirt – that had made the marine look stupid. He seemed angry now – no more hands off. Alaster realised he was about to get a kicking.

Everything contracted down to that fist. Alaster forgot all about levels and jobs and birth-rights; now it was all just surviving the next few moments.

To buy himself time, he edged backwards. He heard the marine laugh and bark something about running away, but he didn't listen. Alaster realised he needed a plan.

The floor. A slight shine, to his left. He didn't look at it directly, didn't dare to – but he knew that bit of it. He'd slipped up there only last week, during games. It was too smooth, too polished.

A glimmer of an idea entered Alaster's head. He stepped backwards and to the left, careful not to look down. Best not to draw attention to the floor.

'Still running, runt?' Thaddeus asked, in a derisory tone.

'Why, am I going too fast for you?' Alaster sneered as best he could. It worked – the marine visibly twitched. 'Catch me if you can, slow-coach!'

Thaddeus dived forwards, feet crashing into the floor. Then he hit the smooth patch – one foot shot out from under him. The Raven skidded and fell to the floor. He recovered almost instantly, rolling toward Alaster and leaping to his feet. His fist came up in one smooth movement-

In an instant of panic, Alaster struck out wildly, to try and block it.

As his hand moved, he realised he was still holding the knife. The marine's fist and the knife converged. There was an almighty thump, jarring Alaster's hand, as the knife-tip and the power-gauntlet collided. With a painful screech the knife skittered over the ceramite.

A sudden urge made Alaster push. Suddenly, he felt the knife shift. It slid into a narrow gap between two plates in the gauntlet. He felt a crunch as something gave way beneath the point. From the Space Marine's wrist, red blood spurted out.

Startled, Alaster leapt back. The knife flew away, wrenched from his hand. He staggered, lost his balance and fell over. He hit the floor, breath knocked out of him. As he lay there, winded, he awaited the thunderous blow that would make everything go away.

It didn't arrive.

Dazed, Alaster looked up. Thadeus was examining his wrist, and the thin sputter of blood leaking from the small wound. The Raven massaged his damaged wrist; even as Alaster watched, the flow staunched.

Nonetheless, the Storm Raven looked up. To Alaster's disbelief, the mighty Space Marine bowed to him. Thaddeus turned and addressed the captain.

'My Lord, the selectee has first blood. As are the rules, I concede.'

He stepped back. The crowd exploded with noise.