Content note: Very-lightly-described torture and gore.

James sprinted into the hallway, his world slowing to a stop as he saw the figure stepping over the threshold. His hand tightened around his wand - of course he had his wand, he never went without his wand, not now, after all these years of war - as he screamed "Lily, take Harry and go! It's him! Go! Run! I'll hold him off!"

The high, cold voice that haunted every Order member's nightmares laughed, and for an instant James stared with pure hatred into the face of the thing that had taken so many of his friends, so many good people, and now would take his family -

"Avada-"

"CRUCIO!"

The instant Sirius thought of James and realized he knew where James lived, he dropped his Firewhiskey and ran out into the night, heedless of the smashed glass on the floor or the protesting barman behind him.

Screams greeted him as his Apparation took him to the front door of James's house. He whipped out his wand, ready to charge in and save James, and saw through the open door -

"Crucio! Crucio, you bastard!"

He watched, his shoulders relaxing despite himself, as James kicked the screaming figure in the face and renewed the Unforgivable yet again. His old friend seemed completely oblivious to his presence; had the snake-faced bastard brought along any backup, James would have been dead in an instant.

But the fiend liked to make a point that he alone could take on an army of "lesser wizards".

For a moment, Sirius savored the sight, but it would be irresponsible to just stand there. James couldn't keep it up forever, and the moment his body was responsive again, the bastard would doubtless seek revenge.

With one swift stomp, he broke the monster's wand beneath his heel. Then he conjured a hacksaw.

And what might the great and terrible Dark Lord do without limbs, eh? Bite James's ankles?

Under different circumstances, some Death-Eater-sympathizer might have tried to get James locked up in Azkaban.

Fortunately, Crouch - whatever else one might say about him - was quite willing to declare James an honorary Auror when he handed over the screaming torso that had once been a Dark Lord. The circumstances called for it. And since Aurors were currently authorized to use Unforgivables... well.

The end of the war was not without its difficulties. Several "upstanding citizens" were caught trying to save their Lord, though the fight apparently went out of some of them when they got a good look at just what remained of him. It was absolutely fantastic how the "Imperius Curses" on them all seemed to wear off the moment the Aurors had them on the ground and disarmed, eh?

It was doubly fantastic when the Aurors finally got one who was both bad enough at Occlumency to fail to conceal information and cocky enough to have neglected to dose himself to the gills with Veritaserum antidote before he ran off with his comrades on the latest failed raid.

Very awkward that it was Crouch's son, though.

James might have felt sadder for him if he hadn't recently had to perform his own "citizen's arrest" of an old friend. It was a bitter thing, sending a former friend off to the Kiss. It was bitterer to know what Peter had done to deserve the Kiss. He, Lily, and Harry weren't the first family Peter had sold out to the Dark Lord. Not by far.

It wasn't even a surprise that Peter proved equally eager to sell out the Death Eaters he knew.

Between Peter and Junior, many masks hit the floor, and those brought in for questioning - the ones who didn't perish in last stands - were all too eager to divulge the identities of their fellows. Some lied, of course, in a final fit of spite, but the presence or absence of their Lord's Mark proved useful for telling the wolves from the lambs.

The knowledge that their Lord, immortal though he might be, was now as helpless and as mutilated as the countless children he had butchered... went a fair ways towards ensuring the cooperation of most.

And to think, all it had taken was the realization that the Cruciatus was two syllables faster than the Killing Curse.

Damned shame that realization hadn't come earlier.

Author's Note: The Killing Curse is infamous for being unblockable, but canon apparently holds that the Cruciatus is as well.

Title comes from the canon scene in Deathly Hallows that reveals the Cruciatus can be cast by a relatively sane mind with no preparation, given enough accumulated provocation.

Before anyone asks: presume James is the Power He Knows Not. As far as being "mark[ed] as his equal"? Hm, who knows. Perhaps when Harry finally puts Voldemort out of his misery, Voldemort bites his ankles.