Disclaimers: "If you don't own Harry Potter, clap your hands!" (wild applause from Eggo Waffles)
Sirius was all for Apparating into the middle of Cirian Blask's living room, Stunning him, flooing him to the Ministry of Magic, cursing his way through the Department of Mysteries, and then tossing the unconscious fellow through the Veil like a sack of potatoes.
However, as he had invited Remus Lupin in on the scheme, this was not to be. Lupin would probably see that everything was planned to the letter before putting a toe out of Grimmauld Place. It had been like that at Hogwarts—James and Sirius would concoct a hairbrained scheme for abusing Snape, and Remus would be the one to tie them down in a chair, look up appropriate jinxes, consult the Marauder's Map, proofread their History of Magic essays, and then untie them to embark on a effectively planned escapade.
"Sirius, you've only just gotten out of Azkaban," said Lupin in exasperation. "It would be pretty pointless to go through all the trouble of coming back to life if you're going to spend the rest of your days in prison for breaking into the Ministry and tossing some poor soul to his doom, especially if said person turns out to be a Muggle."
"Well what do you propose?" said Sirius sardonically.
"First, we need to figure out an alibi for going to Mr. Cirian Blask's home. I mean, we can't just ring the doorbell of a house belonging to someone we've never met and say, 'Oh, hi, we're wizards and there was a mishap in the afterlife so we're going to take you to our place of government and throw you through a curtain in order that my friend here can live a happy and prosperous life.'"
"Why not?"
Remus groaned and banged his head against the wooden table. "Sometimes I wonder how I ever became friends with you."
"Is that an insult? I could pound you."
"Tough words coming from someone who's dead and sleeps with a stuffed animal."
"Hey, I'm not dead now! And I don't sleep with Mr. Wiggles anymore... well, not all the time, anyway..."
Remus rolled his eyes. "Getting back to our original topic... I was thinking we should pretend to be Muggle journalists. We could think up some topic to interview him on, gain his confidence, pretend we're going for a photo shoot, lead him to London and somehow get him into the Ministry, and then sneak him into the Department of Mysteries, whereupon we will toss him through the Veil and Apparate out!"
Remus sat for a few moments, smiling at his brilliant scheme.
"You're losing your touch, Moony," said Sirius dryly. "That sounds like something Peter would have come up with, and that's saying something."
"Have you got a better idea?" his friend replied coldly.
"Well, no..."
"Then let's get going!"
"But supposing he's not a Muggle!"
Remus paused. "Well, that'll be easy. We'll pretend to be Aurors and arrest him..."
"Arrest him?"
"Yes, arrest him. And then we'll take him to the Ministry for 'questioning' about last night's events, and..." Lupin's face died slightly. "... and we'll wing it from there."
Sirius frowned. "This will never work."
"Yes, it will. Now, first we need some Muggle clothes..."
"But what if he's not a Muggle?"
"Aurors dress undercover Muggle-style all the time."
"Ah, I see," said Sirius. He had actually never seen an Auror dress undercover Muggle-style, but Remus was the one who knew things like that. "I think I have a few things upstairs... and some of the Weasley kids left some clothes."
"You expect those to fit us?"
"Nothing an Engorgement charm won't rectify."
Lupin shrugged in assent, and the two tramped up the stairs of the ancestral Black home.
Twenty minutes later, Sirius and Remus were dressed in what they evidently assumed was Muggle-style. Lupin actually looked relatively normal, though his choice of purple pinstriped trousers and a bright green Weasley sweater was slightly outlandish. However, compared to Sirius, who was wearing Moody's bowler hat, a dinner jacket, and checkered athletic shorts, Remus looked as unassuming as any respectable Muggle.
"I swear they don't wear those things anymore," Remus whispered to Sirius, jerking a head at his hat, as they walked down the London street. A few people driving cars and several pedestrians were eyeing them strangely, though neither wizards noticed.
"Sure they do, Mad-Eye wears it every time he goes into Muggle territory," Sirius replied cheerily, adjusting the hat.
"I think that's just to hide his... oh, there's the house," said Lupin, pointing at the derelict brick building. On the outside, it looked very much like Sirius's, minus the snake-encrusted black door. They ascended the doorstep cautiously, when Sirius stopped abruptly, nose wrinkled.
"Cat," he said disgustedly. There was a heavy odor of felines surrounding the house, which any wizard with the ability to transform into a dog would recognize. Other than Crookshanks, a notable exception, Sirius despised cats.
"Maybe Mr. Blask's a cat lover," said Remus.
"Why would anyone be a cat lover? Dogs are so much more agreeable."
"Cats are low-maintenance."
"They bring dead rodents into the house."
"So do owls."
"But owls are nicer than cats."
"Look, are we going to stand around arguing about cats, or are we going to ring the doorbell?" Sirius paused for a moment, whereupon Lupin groaned and pressed the glowing white button.
Ding-dong!
There were sounds of activity from within the house, and the door creaked open slowly.