Harry Potter and the Methods of Rationality

not be seen.

There was a faint sound as of wind or whooshing, and then the sound of Bellatrix's invisible body coming to rest on a stair further below, she had no place in this except -

"Stay still," said the cold high whisper, "stay silent."

There was stillness, and silence.

Harry pressed his wand against the side of the metal step just above him. If he was anyone else he would have needed to take a Knut out of his pocket... or rip off a bit of cloth from his robe... or bite off one of his nails... or find a speck of rock large enough that he could see it and solid enough to stay in one place and orientation while it touched his wand. But with Harry's almighty power of partial Transfiguration, this was not necessary; he could skip that particular step of the operation and use any material near to hand.

Thirty seconds later Harry was the proud new owner of a curved mirror, and...

"Wingardium Leviosa," Harry whispered as quietly as he could.

...was levitating it just above the steps, and watching, in that curved surface, almost the whole corridor where Professor Quirrell invisibly waited.

Harry heard it in the distance, then, the sound of footsteps.

And saw the form (a little hard to see in the mirror) of a person in red robes, coming down the stairs, entering the seemingly empty corridor; accompanied by a small Patronus animal that Harry couldn't quite make out.

The Auror was protected by a blue shimmer, it was hard to see the details but Harry could see that much, the Auror had shields already raised and strengthened.

Crap, thought Harry. According to the Defense Professor, the essential art of dueling consisted of trying to put up defenses that would block whatever someone was likely to throw at you, while trying in turn to attack in ways that were likely to go past their current set of defenses. And by far the easiest way to win any sort of real fight - Professor Quirrell had said this over and over - was to shoot the enemy before they raised a shield in the first place, either from behind or from close enough range that they couldn't dodge or counter in time.

Though Professor Quirrell might still be able to get in a shot from behind, if -

But the Auror halted after taking three steps into the corridor.

"Nice Disillusionment," said a hard male voice that Harry didn't recognize. "Now show yourself, or you'll be in real trouble."

The form of the sallow, bearded man became visible then.

"And you with the Patronus," said the hard voice. "Come out too. Now."

"Wouldn't be smart," said the gravelly voice of the sallow man. It was no longer the terrified voice of the Dark Lord's servant; it had suddenly become the professional intimidation of a competent criminal. "You don't want to see who's behind me. Trust me, you don't. Five hundred Galleons, cold cash up front, if you turn around and walk away. Big trouble for your career if you don't."

There was a long pause.

"Look, whoever you are," said the hard voice. "You seem confused about how this works. I don't care if that's Lucius Malfoy behind you or Albus bloody Dumbledore. You all come out, I scan the whole lot of you, and then we talk about how much this is going to cost you -"

"Two thousand Galleons, final offer," said the gravelly voice, taking on a warning undertone. "That's ten times the going rate and more than you make in a year. And believe me, if you see something you shouldn't, you're going to regret not taking that -"

"Shut it!" said the hard voice. "You've got exactly five seconds to drop that wand before I drop you. Five, four -"

What are you doing, Professor Quirrell? Harry thought frantically. Attack first! Cast a shield at least!

"- three, two, one! Stupefy!"

Bahry stared, a chill running down his spine.

The man's wand had moved so fast that it was like it had Apparated into place, and Bahry's stunner was currently sparkling tamely at the end of it, not blocked, not countered, not deflected, caught like a fly in honey.

"My offer has gone back down to five hundred Galleons," said the man in a colder, more formal voice. He smiled dryly, and the smile looked wrong on that bearded face. "And you shall need to accept a Memory Charm."

Bahry had already swapped the harmonics on his shields so that his own stunner couldn't pass back through, already tilted his wand back into a defensive position, already raised his hardened artificial hand into position to block anything blockable, and was already thinking wordless spells to put more layers on his shields -

The man wasn't looking at Bahry. Instead he was poking curiously at Bahry's stunner where it still wavered on the end of his wand, drawing out red sparks and flicking them away with his fingers, slowly disassembling the hex like a child's rod puzzle.

The man hadn't raised any shields of his own.

"Tell me," the man said in a disinterested voice that didn't seem to quite fit the rough throat - Polyjuice, Bahry would have called it, if he'd thought that anyone could possibly do magic that delicate from inside someone else's body - "what did you do in the last war? Put yourself in harm's way, or stay out of trouble?"

"Harm's way," said Bahry. His voice kept the iron calm of an Auror with nearly a hundred full years on the force, seven months short of mandatory retirement, Mad-Eye Moody couldn't have said it with any more hardness.

"Fight any Death Eaters?"

Now a grim smile graced Bahry's own face. "Two at once." Two of You-Know-Who's own warrior-assassins,