To understand Transfiguration in its most complete sense, the witch or wizard must recall the basic transitive property -

Andromeda stared hopelessly at the black words scratched on the worn parchment. She had been reading the same page for a quarter hour - each passing tick of the clock a reminder of the fast-approaching school year and the N.E.W.T. classes that accompanied it - and had not absorbed any of it.

To understand Transfiguration in its most complete sense, the witch or wizard must recall the basic transitive property, which states if 'a' is related to 'b' and -

"AIIIIIIIIEEEEEEE!"

The gleeful screech echoed down the hall and shook Andromeda from her deep concentration. She tensed, staring at the doorway and waiting for further noise. Hearing none, she sighed, turned back to her Transfiguration schoolbook and resumed chewing on the tip of her quill.

- the basic transitive property, which states if 'a' is related to 'b' and - 'b' is related to 'c' then 'a' is related to 'c.' It is on this simple yet effective law that -

"Andromeda! ANDY! Come see this!"

The second outburst jolted her enough to break the quill in half. With a string of curses that would have made Bellatrix proud, Andromeda pinched the bridge of her nose and took a deep breath.

"I'm in the study, Narcissa! Some of us are studying for our N.E.W.T. examinations, while others do not have the decency to shut up," She yelled back through gritted teeth.

The blonde hustled into the room, a sleek black box tucked under her arm and a thick stack of envelopes in her hand. Andromeda could see the corners of her sister's mouth twitching in excitement as she fought to regain her flawless upper crust composure. Andromeda peered at her sideways as she flipped through the pages.

"Honestly, Cissy, I've never heard you more than sneeze, and you choose now to bellow around like a dying Jobberknoll."

Narcissa ignored this and instead glided over to the table and ceremoniously dropped the box on her sister's notes and books. Twilfitt & Tattings, Inc. shimmered in green across the lid. With a tap of Narcissa's wand, the silk ribbon unraveled and receded, and the black panels dissolved into a shower of silver stars. A sheen, emerald gown slowly unfolded and levitated over the space the box occupied moments ago.

"Bolivian vicuña with golden weave," Narcissa smirked, smugness dripping from her every word. "Only nine others in the entire world."

"You always find a way to put Father's Galleons to such good use," Andromeda sighed, watching the dress rotate above her head.

"Well, it's certainly more acceptable than purchasing embarrassing amounts of literature you don't even need," Narcissa said, glancing at her sister's teetering stack of books.

"It would do you well to spend a bit more time with your required text if you have any hopes of landing a respectable career beyond Hogwarts, Cissy," Andromeda said, waving her wand and sending the gown back into its box.

"And it would do you well to spend a bit more time shopping with Mother and me if you have any hopes of landing a respectable husband beyond Hogwarts, Andy," Narcissa snapped.

Andromeda opened her mouth to retort but closed it quickly and grabbed a fresh quill.

"I really do need to get back to studying," she muttered.

Narcissa, sensing a victory, smirked again and placed a lavender envelope on her sister's lap.

"I must say I am pleasantly surprised that you have subscribed to Witches' Weekly," said Narcissa, nodding towards the envelope. "I figured it was below that insufferable intelligence in which you take so much unnecessary pride."

Andromeda watched her sister leave the leave before tearing it open. She recognized the large, wide handwriting at once and couldn't suppress a grin and accompanying flutter of happiness in her stomach.

My Dear Andromeda,

If you are reading this, it means that brilliant Witches' Weekly disguise charm worked perfectly. Your solutions to our small communication problem are getting more and more clever, my darling, even though I am slightly upset you wouldn't let me use the boobytrap I had originally planned. Picturing your prim little sister with Stinksap dripping off her face was quite satisfying.

As much as it pains me to say, we probably cannot afford to communicate as often until school resumes. Messenger owls are hard to come by in the Muggle world, and I don't want any of your family friends tracing Ermete back to my home. If we get caught, your parents will lock you away forever, and I will have to find another pureblood princess to woo with my Muggleborn charms.

Can you imagine if we were named Head Boy and Head Girl together? Just think of all those extended hours on the grounds at night we're allowed...one's mind does wonder! I don't think we could get that lucky, though. My Galleons are on Fenwick and that Ravenclaw Jeanetta Armbruster.

I thought about your plan, and I just don't think it's reasonable, Andromeda. Polyjuice potion ingredients are very rare, and it would be near impossible to restock. Plus, I can imagine your sisters turning up at the house at a moment's notice, and I might be discovered in my boring Muggleborn form before I had a chance to disguise myself. I know what your next suggestion might be, but I just cannot accept it. I cannot be responsible for doing that to you.

What if I get old and fat and absolutely horrid to behold and you rue the day you ever made that decision?

Write back soon. All my love,

T

"There you are."

Andromeda jumped slightly in her seat, and she felt the paper rip from her hands. Fear and adrenaline surged through her, and she braced for the pending explosion.

"Witches Weekly, Andy? Please don't tell me Narcissa has used my absence as a campaign to convert you."

Bellatrix plopped down in an armchair across from her sister, tossing the paper on the floor and inspecting her wand. Andromeda's heart rate slowed to normal as she stared at the letter, giving silent thanks that the charm working a second, more crucial time.

"I had to practically pry myself away from Druella," Bellatrix continued. "If I have to dodge one more question about giving her a grandson - Andromeda Black, are you crying?"

Andromeda tore her eyes from the magazine and casually wiped her cheek.

"No, I must have gotten some dust in my eye," she lied quietly.

Bellatrix nodded knowingly. "I've always said the house elves don't earn their keep around here. The way they clean things, you'd think they'd be using Mudbloods as rags."

Andromeda shot her a look. "Bella, I was studying, you know."

Bellatrix barked a laugh. "Studying what, Andy? 'Nine Ways to Win Your Warlock'? What's wrong with you anyway? I'm gone for three weeks, and you barely flinch when I return. Has Druella gotten to you, too?"

Andromeda waited for the weight to lift. She waited for presence of her older sister to solve every problem, like it had so many times in the past with fights with Druella or nerves about a test or reaching her limit of dealing with Narcissa's nagging without Bella there to soften the blow. She studied her sister's face, so like her own, but it looked thinner. Hollowed. Her hair looked slightly frayed, and it blended in with the dark cloak with long sleeves that hid her controversial secret. The relief didn't come. So instead, Andromeda teased.

"What is this? Bellatrix Lestrange scorned by lack of affection?"

"Oh, please," Bellatrix yawned. "It's just that you and I both know it's such a bore around here without me."

Andromeda knew her silence confirmed her sister's suspicions. Things were noticeably quieter without Bellatrix around. And quiet led to seclusion. And thinking. Irrational thinking...

She pushed the thoughts aside.

"Our cousins are paying us a visit today," said Andromeda, moving to sit on the arm of Bellatrix's chair. "Walburga is under the impression that I am going to be named Head Girl and is calling for an early celebration."

"More like an early mourning," Bellatrix scoffed. "We must resign the fact that you ruined the Black Family name of impertinence at Hogwarts by being so well-behaved."

"Don't be ridiculous," Andromeda said. "Phineaus Nigellus was headmaster."

"Most hated headmaster, if I recall correctly! Like a proper Black!" Bellatrix laughed again, and looked up at her sister. Seeing Andromeda's troubled face, Bellatrix rolled her eyes. "Come off it, Andy. I was joking. No one could possibly hate you. Unless it's because of your association with me, in which I would take a great deal of pride."

They sat in silence for a while, Andromeda fighting the internal demons that did not quite manage to subside in her sister's presence. The pressure was digging into her, like a jagged tattoo threatening to carve out her secret. She fought to keep her breathing in time with the ticking clock, until a sudden CRACK! filled the room.

"Mister and Mistress Orion Black wish to formally announce their arrival!"

The abrupt arrival of Kreacher and his gravely voice caused Bellatrix to curse and spring to her feet, practically knocking Andromeda off the chair.

"Yes, yes, alright then, elf," she said, waving her hand dismissively as Kreacher bowed out of the room. She turned to Andromeda, grinning wickedly. "I suppose it's time to torment Druella with our hopeless social missteps."

...

Narcissa Black was not pleased.

After a quick look at Druella's rigid posture and pursed mouth, she could tell her mother felt the same way.

Aunt Walburga had come sweeping in, loudly proclaiming Andromeda's achievements and the re-installation of the Black Family honor at Hogwarts. And Andromeda had calmly explained that she had not yet been named Head Girl and would not know for a few weeks.

"Balderdash," Walburga said, waving her hand dismissively. "I know a Head Girl when I see one, Andromeda. When a Black becomes a prefect, that is the next natural step. The school knows this, my dear niece."

"You forget, Aunt Walburga, that things have changed since your tenure at Hogwarts," Bellatrix said acidly. "With Albus Dumbledore in charge, status and tradition are as good as the mud in his half-blood veins."

It was then, Narcissa noted, that the two erupted into one of their typical anti-Muggle, anti-Mudblood rants, with an occasional supporting comment from Uncle Orion. After some time, her mother attempted to regain control of the conversation by summoning the tea and noting that Sirius must be excited to begin his schooling, but Walburga and Bellatrix paid no mind.

So there they were, an hour later and the conversation as strong as ever and Bolivian vicuña gown shockingly under-appreciated. Narcissa glanced hopefully at Andromeda, who proved to be useless as always, entertaining Sirius and Regulus with flashy wand tricks. She turned back to her aunt and oldest sister, crossing her arms and sinking an inch lower in her chair. Not too low, though. A lady must be a lady, even when displeased.

"I have always maintained the school will be forever tarnished until the day Mudbloods are turned away at the door," Walburga concluded, gesturing with a half-eaten biscuit.

"I have a far better solution," Bellatrix said in a hiss so quiet that Narcissa thought she must have been the only to hear.

Sensing a break, Narcissa nodded politely and sipped her tea. Finally, she thought. It is over.

"How can you tell?"

Everyone's heads turned. It was Sirius, who had abandoned Andromeda's transfigured snake to join the conversation.

"What was that, boy?" Walburga snapped.

"How can you tell if the witch or wizard is a Muggleborn?" Sirius asked.

Walburga's face flushed a deep shade of crimson and she shot a nervous look at Bellatrix.

"Forgive my son's foolishness-"

"That's alright, Walburga, he's still a child," Bellatrix said with a smile that did not quite reach her eyes.

She turned towards Sirius. "Allow me to give you a more important lesson than you'll ever learn at Hogwarts, dear cousin. Observe."

And with a flick of her wand, a large, sparrow appeared in her palm, chirping happily.

See how he is strong, beautiful, proud," Bellatrix said. "He is the representation of everything a sparrow should be. He represents nobility and order. He is the rightful master of his kin."

With another wave, another sparrow appeared, considerably smaller and sicklier looking than his counterpart. The bird wheezed and staggered around on the table. Regulus joined his brother's side, intrigued at the new magic.

"Now observe this one," Bellatrix said, her voice low. "He is ugly. Weak. Diseased. He is a threat to other sparrows. His offspring's offspring jeopardize the future of the species."

The room was deathly silent. Narcissa felt a foreboding lump from in her throat but could not tear away from the scene. She saw movement out of the corner of her eye; Andromeda was pulling Regulus back to her, trying to catch his fascination once more.

"It is because of this that the first sparrow must destroy any threats to his descendants," Bellatrix continued, her voice dropping to a whisper. "He must do it for the greater good of his kin's future."

Sirius was not consoled. His brow wrinkled.

"I overheard a girl in Diagon Ally talk about her Muggle parents," he said, staring intently at the two birds. "She looked no different than anyone else there. These sparrows are easy to tell apart because they don't look alike on the outside. So how can you tell with people?"

Silence.

Then…

In one swift motion, Bellatrix unsheathed a small dagger from her robes and plunged it into the breast of the smaller sparrow. With a rough jerk, she sliced through the bird. Thick, rancid mud and waves of spiders spilled out of the gash as it crumpled.

Andromeda succeeded in whisking Regulus out of the room as he started to cry in fright, while Narcissa, Druella, Orion and Walburga flew out of their seats to avoid the wave of spiders. Sirius and Bellatrix, however, remained unmoving, face to face over the ruined sparrow.

"Simple," she growled. "Look on the inside."