Regulus watched in silence for a moment, then tapped his wand again, and the werewolf suddenly found he could breathe.
He dragged in air greedily, huge gulps that finally filled his lungs. Oxygen slid back into his blood, and the dizzy haze in his head began to ease.
He lay there like a drowning man hauled out of the water, gasping wildly. Every inhale went as deep as he could force it, every exhale trembling with the shock of survival.
He didn't notice what was happening inside him.
The air he'd taken in, after the exchange was done and the carbon dioxide pushed out, left residue in his alveoli that began to change.
It condensed, gas becoming solid, invisible turning into something real.
Tiny crystals formed, sharp-edged and hard, almost like quartz.
In essence, they were the same stones that had exploded from the ground earlier, only ground finer, shaped sharper.
The first stab of pain hit on his tenth breath.
The werewolf jerked and started coughing, trying to hack the foreign matter out, but the crystals had already embedded themselves into the walls of his lungs. Every cough only drove them deeper.
It felt like someone had stuffed his chest with broken glass. Every breath tore.
Regulus released the transfiguration.
The werewolf still coughed, and the fresh air he drew in now behaved normally, but the crystals from before were still lodged inside him, and they would stay there.
Unless someone used magic or surgery to remove them.
A werewolf in Knockturn Alley couldn't afford that kind of treatment.
He lay curled on the ground. Blood began to thread through the saliva he spit up. The pain folded him in on himself, hands clamped to his chest so hard his nails bit into skin.
Regulus observed calmly, satisfied.
This was what real combat was for.
Testing ideas.
The cold wizard saw the werewolf go down and his face shifted.
He whipped his wand and summoned more than a dozen shadowy tentacles from the ground. They crawled out of the darkness itself, lined with suckers. Inside each sucker were dense rows of tiny teeth.
The tentacles lunged from every direction, sealing off every route of escape.
They moved with startling speed, and in a blink they were already in front of Regulus.
Regulus didn't move.
He simply flicked his left hand again, as casually as brushing dust out of the air.
Magic surged from him, and his whole body seemed to become a source of light. Silver-white radiance seeped through his skin, gathering in front of him into a barrier that looked soft, almost gentle, but felt absolutely unbreakable.
The shadow tentacles struck it and began to hiss as they dissolved.
Wherever they touched the silver light, they started to fall apart, solid becoming mist, mist becoming nothing.
One after another, all of them vanished within two seconds, leaving no trace behind.
The cold wizard's eyes went wide. For the first time, real fear cracked his expression. He tried to step back, but his legs might as well have been nailed to the ground.
"That's impossible…"
He didn't get to finish.
Regulus apparated.
One moment he was standing in the alley, the next he was right in front of the man.
He put his wand away. Then he lifted his right hand, extending his index finger.
A single point of glaring crimson light gathered at his fingertip, painfully bright in the dim alley.
Crucio.
Regulus was not about to cast it with his own wand on a living person.
Not yet.
He touched the man's forehead lightly.
The crimson light sank in, slipping through skin, through bone, straight into the deepest part of the brain.
The cold wizard went rigid.
His eyes opened to their absolute limit, as if they might pop out of their sockets. His pupils shrank to pinpoints, the whites turning webbed with red.
Every muscle in his face twitched. His mouth pulled crooked. His left eyelid spasmed violently.
Under his skin, tiny ripples moved like waves, as if countless insects were crawling between flesh and bone.
He tried to scream, but it was like his voice had been locked away. No sound came out, only a thin clicking noise deep in his throat.
Saliva spilled from the corner of his mouth and ran down his chin, dripping onto his black robes and spreading into a dark wet stain.
Regulus held it for three seconds.
Three seconds was enough for the full tide of Crucio to roll through the man.
Every nerve shrieked. Every bone felt crushed. Every cell burned.
Then Regulus pulled his finger away, and the crimson light vanished.
The cold wizard collapsed. His body jerked in uneven spasms, limbs twitching without rhythm, fingers curling into clawed shapes.
Spit mixed with snot and tears smeared his face. His eyes lost focus, staring blankly at the lead-gray sky, pupils blown wide, mind broken apart.
Regulus glanced down at his right hand.
There was no mark at all. Smooth skin. Clean nails. That crimson point might as well have been a hallucination.
A standard Crucio.
The effect was excellent.
Crucio was an Unforgivable Curse, but it wasn't difficult to cast. Harry Potter had managed to use it on Bellatrix in fifth year. Regulus had no reason to be worse than that.
He swept his gaze across the alley.
Four enemies.
All of them out of the fight.
From start to finish, it had taken less than two minutes.
Regulus stood in the middle of the alley with steady breathing. His robes were neat. Even his hair hadn't come loose.
---
Orion remained by the shop entrance, hands clasped behind his back, watching without a word.
From the moment Regulus stepped out alone to the moment all four opponents went down, Orion saw every second.
He was pleased. Regulus's performance was even better than he'd expected.
His spellwork was smooth. His choices were flexible. He used the environment well, seized timing perfectly, and his coldness under pressure exceeded Orion's predictions.
But Orion didn't relax.
His attention stayed locked on the four bodies, especially the cold wizard who'd been hit with Crucio.
Crucio was agony, but it didn't always completely erase a person's ability to fight.
Some wizards went through special training. Some could retaliate while under it.
Carelessness got people killed everywhere. Knockturn Alley was worse than most.
Regulus stood where he was, looking down at what he'd made of them.
The tall wizard was still struggling uselessly, but his movements were growing weaker. The barbed rope had already drained most of his life away.
The short wizard clutched his sliced wrist, eyes unfocused, muttering something under his breath.
The werewolf knelt on the ground. Every breath came with violent coughing, the spit flecked with blood.
The cold wizard lay twitching in fits, eyes turned toward the sky, pupils blown wide.
Regulus waited about ten seconds, then looked back toward the shop entrance.
Orion was still standing there, hands behind his back, not coming closer, not speaking, simply watching.
Regulus understood immediately.
The fight hadn't been the only test.
His father wanted to see what he did next.
How he handled enemies who were down. How he assessed threat. How he made a decision.
That was part of real combat too, and it might have been the more important part.
In that case, fine.
Regulus lifted his wand again and aimed it at the nearest target, the cold wizard who'd been struck by Crucio.
He drew in a breath and spoke the incantation clearly, evenly, without emotion.
"Avada Kedavra."
Green light gathered at the tip of his wand.
But at the instant it was about to fire, there was a sharp crack in the air, and Orion appeared beside him.
Orion lifted his right hand, caught Regulus's wrist, and pressed down.
The green flash shot wide, skimming past the cold wizard's shoulder and slamming into the wall behind.
The spot it hit turned instantly ash-gray, then burst apart, stone blowing outward.
Orion kept his hand on Regulus's wrist and turned to stare at his son, confusion written across his face, along with shock he couldn't quite hide.
Was there something wrong with this boy?
The Killing Curse?
Orion didn't care where Regulus had learned it. The family library held plenty. So did other places.
What he couldn't understand was the sheer… decisiveness.
Then he saw Regulus's expression.
There was something almost teasing in it, close to amused. A spark in those gray eyes. The faintest curve at the corner of his mouth.
Orion froze for a heartbeat.
Then he understood.
He'd been played.
Regulus hadn't intended to kill anyone, especially not with his own wand.
The casting posture, the incantation, the green light, all of it had been real, but it was meant for Orion's benefit.
For no reason other than entertainment.
It was Avada Kedavra. As long as it wasn't aimed at a person, practicing it wasn't that big a deal.
Orion released Regulus's wrist.
His face returned to something close to blank, but there was a small, unexpected warmth in him.
His son had actually joked with him.
In eleven years, it was the first time.
Regulus was usually too mature, too steady, too unlike a child. Seeing a flicker of mischief, even like this, made Orion think it was… good.
"That isn't how Avada Kedavra is used." Orion kept his voice as calm as he could, giving away very little.
"I know." Regulus lowered his wand, then paused, and added deliberately, "There are records in the family library. Hogwarts's Restricted Section has it too. If someone wants to learn it, they can.
And the curse itself isn't difficult. The hard part is having the will to kill."