A Study in Magic: The Application
by Books of Change

Warning/Notes: This is the sequel to A Study in Magic, which is a BBC Sherlock and Harry Potter crossover AU posted here. The HP timeline and BBC Sherlock's timeline were shifted forward and backward to match up. One major BBC Sherlock character's gender was changed for the sake of the plot. Readers beware!

ADDITIONAL WARNING: this chapter contains violence. The section is marked with two "—oo00oo—". Proceed with caution.

Chapter Twenty One: Declaring War

The local constabulary swarmed the graveyard not long after the fight ended. Jason Shin had just enough time to transfigure John's weapons into rocks and hide his and Harry's wands.

Sherlock got airlifted to a trauma centre in Bristol while Harry, John, and Jason got patched up at a local A&E. Jason Apparated them to the hospital Sherlock got admitted to as soon as they were released. Then, per John's orders, Jason went looking for a discreet place where he could call Snape's old electronic phone and tell Dumbledore about the attack.

Harry and John waited in the lobby, sitting on plastic chairs with two empty seats between them. Harry wanted to say something to John but had no words. John, in turn, refused to speak.

Mycroft showed up two hours after the attack. He raked his eyes over John first, taking in the bandages, the bruised knuckles and whatever else. Deducing, presumably, everything that had happened from these tells.

At length, he nodded—acknowledging or thanking John, Harry didn't know. Then Mycroft shifted his grey eyes at Harry, and Harry knew exactly what he was thinking.

Mycroft didn't bother to scan his person. He just pinned Harry down with an icy stare and let him see the emotions burning within them.

Let him see the hatred.

"Get out," Mycroft spat.

Harry left without protest, knowing the next time he saw Mycroft, if ever saw him again, it would not be as uncle and adoptive nephew.

It would be as enemies.


It was dark outside when Harry left the hospital building. He stood by the curb, not knowing what to do with himself and worried sick about John and Sherlock.

He didn't think about what happened at the graveyard. He couldn't. Not without going mad.

A long time later, the sliding doors to hospital's main entrance opened and John walked out.

She stood next to Harry an arm's length away. The distance hurt him—it felt like a goodbye.

"Jason will take you back to Hogwarts," John said, staring at the curved driveway in front of them … not at Harry.

"You're not going with me?" Harry asked. The hurt intensified.

John shook her head. "I need to take care of something."

"But you'll come back?"

John didn't answer.

"How is Sherlock?" Harry asked, after a long bout of quiet.

John's lips trembled. Instead of an answer, she shoved an envelope into Harry's hands. Then John turned heel and marched back inside the hospital.

Harry pulled out the letter inside the envelope. The paper had lots of creases and a large damp spot. Like … like someone crumpled it to her face and wept into it. The ink was smudged, but the words were still legible:


I write these lines in case the worst happens. Though I have little stomach for nostalgia, I find myself compelled to write paragraphs of reminisces before I move on to important things…

I hold the Chinese Acrobat Case—the one you titled "The Blind Banker" on your blog—with particular fondness. It was this case that made me realize I wanted you as a fixture. You probably don't recall, but before Sebastian sent me his email, you told me you're headed for the shops and asked me if I wanted anything. I told you I don't eat while on a case, that digestion slows me down. You said to me: Sure, I understand the fasting principle. But why not do what runners do and eat high-carb, low-fibre snacks so the hunger pangs don't slow you down either.

Never had I met someone whose temperament was so congenial to mine and whose insights came as a perpetual surprise.

It was this same case that led me to discover your alarming habit of falling into coma-like slumbers. I dismissed the first instance, which gave the acrobat the opportunity to kidnap you and hold you hostage, as common human weakness. Then the day after we apprehended the culprit, I found you still asleep at noon.

You would not wake up. Nothing I did woke you up. I called 999. The EMTs called you my girlfriend. I didn't correct them.

You slept for five days, and when you woke up at last, you were surprised to see me. We both knew you didn't think I would care. But I did. Those five days were the second most terrifying of my existence. I still shudder when I recall them.

I know you are now wondering what I consider the most terrifying of my days. You must know: they were those days before, during and after Moriarty's heist.

We both noticed you were falling asleep more often and for longer since the Baskerville HOUND case. I knew you were preparing for the day you would not wake up again. I also knew since the Adler case you are the only woman for me and that whatever days we had remaining, I wanted them.

I planned the end, you know. Since we fled from the police who came to arrest me. You got the scheduled text about Mrs Hudson while we hid in Bart's. You were supposed to leave so I could confront Moriarty alone. I didn't expect to survive the encounter.

You refused to leave. You said to me: you are a machine! Christ alone knows why, it's not like you care, but I don't want to spend what's probably my last hours anywhere else except with you.

I wasn't planning on proposing to you then, but it seemed like the logical conclusion to the unfolding events. And it should've been, except you fell asleep, you goddamn inconvenient harpy.

I did not confront Moriarty. I could not. Instead, I took you away and watched you sleep while my work and reputation burned to ashes around me. Did I care? No. Mere trifles compared to the regret of "not making it legal before she clues in," as Lestrade would say.

I confess to this day I don't know if you really believed me when I told you to foil Moriarty I needed a new name and identity, and the quickest legal way to achieve this was us getting married. You had just woken up and the boredom of waiting for you to regain consciousness had driven me witless. And yes, John, the dates I took you to show you my sincerity were atrocious. I will not say this again.

If I were a wizard, I would recall the look on Mycroft and Lestrade's faces when we tricked them into signing our marriage certificate as witnesses to produce a Patronus.

Tell Harry and Benedict they are the children I never knew I wanted. Everything Harry may need to get rid of LV is in pigeonhole V, in an envelope inscribed "Voldemort". I've updated my will and handed it to Mycroft. Send Mrs Hudson, our friendly neighbourhood werewolf, and pet dog my regards. Finally, I pray and hope it's another magic induce coma, not my death, that brings this letter to you. And believe me to be, my dearest friend and wife,

Very Sincerely Yours,

William Sherlock Scott Watson

Harry had thoroughly ruined the letter with his tears when Jason found him.


John felt about as much as a concrete wall would feel if it got punched at when she found Sirius Black sitting in the black car waiting for her.

"You will not stop me from making poor life choices," John said emphatically.

"I'd be a hypocrite if I did, M'Lady," Sirius replied.

John let out a snort. Then she ducked, sat next to Sirius, and shut the door. The car started to move immediately after.

They reached the motorway without anyone saying a word. John unzipped her personal armoury: a backpack Harry charmed to be feather-light, waterproof, bulletproof, fireproof, and, most importantly, to have virtually unlimited storage capacity.

John took out a long, slender case that contained a sniper rifle and a scope. The rifle had been enchanted to be honest to God soundproof; not even the shooter would hear anything when they fired. It would never overheat either. Thus, you were limited to the number of bullets you had.

It was unfortunate no one figured out (yet) how to make clips that refilled themselves: that would've been nice.

John set the case on her lap. Then she pulled out her copy of the Death Eater Index and flipped it to Appendix B, Death Eaters who escaped conviction during the first war.

She scanned the list: Stuart Avery, Victor Crabbe, Gavin Goyle, Igor Karkaroff, Lucius Malfoy (John made a mental note to cross his name out), Alastair Nott, John Travers, Corban Yaxley…

John considered her options. Made a decision.

"Show me the entrance to the M.O.M., Sirius."

John greeted the morning sun inside a boarded-up building in White Hall. Across the street, one could observe a throng of oddly dressed men and women leaving an alleyway that contained an abandoned theatre … all of them heading to the steps leading to a public toilet.

John watched her mark leave the alleyway through the scope. He walked briskly, surely, not unlike Sherlock.

Sherlock, who lay dying because of the monster the mark worked for.

John took aim. She knew what statement the shot would make: We Muggles know what you are, who you are, and how to find you. And we can kill you.

A declaration of war.

John pulled the trigger.


Harry sat numbly in his seat as news headlines flashed before him.

Ministry of Magic official Corban Yaxley killed on his way to work! Assassination suspected!

Convicted Death Eaters Antonin Dolohov, Dresden Gibbon, and Alto Jugson found dead with four others in West Country!

Minister for Magic Rufus Scrimgeour and Head of the Department of Magical Law Enforcement Pius Thicknesse found to have been under the Imperius Curse! Culprit unknown!

All around him, student and staff were watching the same news and reading the same headlines from their phones. Not Harry; he lost his phone yesterday when… he got attacked. It may still be in a small graveyard in West Country.

Harry wasn't sure if he'll ever go back there to find it.

"Snape's not here," Hermione whispered. She and Ron had been tiptoeing around him and speaking in hushed voices since he returned with only Jason. "Malfoy isn't here either."

Harry froze. He knew why Snape and Malfoy weren't in the Great Hall like the rest. Snape must've taken Draco aside to tell him Lucius Malfoy was dead.

He still couldn't believe it: Lucius Malfoy, dead.

He was dead and gone and it was Harry's mother who killed him. Malfoy was never going to see his father again. Whether Draco had been close to Lucius, Harry didn't know. But the fact still remained: his father was dead.

John had to defend herself, Harry thought desperately. If she hadn't fought back, Lucius Malfoy would've…

Yet even though the mere idea of John murdered or worse by Death Eaters left him mute, shaking and sick with terror, even though nothing would convince him John acted in anything other than self-defence, these facts stood out like an accusatory beacon:

His mother took a life; made someone a widow and her son fatherless.

Worse, she shot him when he could no longer do anything. Killed him in cold blood.

Killed six people just as mercilessly.

Harry had known John had killed people in the past. He knew her military record, knew she shot the cabby in A Study In Pink case and heard her threatened to kill people with serious intent. But until that hour he'd seen her kill seven Death Eaters, seen John gun down Lucius Malfoy, Harry didn't really know she could kill.

How was he to take this?

Something touched his cheek.

Harry looked up and saw Julia offering a phone.

"Call your mum," she said.

Harry stared, hearing the words but not comprehending.

"Do you want your mother back?" Julia asked.

Harry nodded. He wanted that more than anything.

"Then call her," said Julia simply.

Harry took the phone.



Sirius watched John Watson take apart a sniper rifle while ignoring her phone. It had been ringing on and off since Yaxley's death hit the morning news. Sirius didn't know who was calling. Jacqueline had not yet made magical mobile phones that could assign specific ringtones per caller.

The call went to voicemail. All was quiet and still for a second. Then something large and silver burst out from Sirius's magical mobile phone.

Graceful and gleaming, the lynx landed lightly on the concrete floor. The Patronus's mouth opened wide and it spoke in the loud, deep, slow voice of Kingsley Shacklebolt.

"Death Eaters infiltrated the Ministry while under lockdown. Scrimgeour is dead."

John finished packing the disassembled rifle. Shut the case with a click. Then she looked at Sirius with dead eyes.

"Can you get me in?"

Sirius nodded. "I still have Lestrade's tokens."

John shoved the case back into her portable armoury. Then she rearmed. Stripped down and wore full combat gear: boots, uniform, armour, black balaclava, and helmet. Finally, she took out a machine gun of terrifying size from her armoury and loaded it.

"Let's go," she said after strapping on the gun.

They left the building, crossed the street, and marched into the men's toilet. Sirius handed John a token. She shoved it into a slot, entered the stall, and stepped into a toilet as natural as can be.

John pulled the chain and vanished. Sirius followed. It was all he could do.

He stepped out of the fireplace and found John scanning the empty hall. Her gun was pointing at the ground, and her finger was off the trigger.

"Where?" she barked.

"Let me ask." Sirius whispered to his phone: "Where are they, Kingsley?"

"Level one, ministry staff, media room," Kingsley replied back. "They're making an announcement."

"Level one!" Sirius hissed. "There are lifts at the other side of the Atrium!"

John didn't move. "Lifts: bad. Stairs?"

Sirius repeated the question to Kingsley.

"No stairs, sorry. Just take a lift. There's no one out."

"F**k this place and its sh**ty security," John snarled before jogging towards the Atrium.

The gates were locked. John kicked one open. Sirius had a brief thought John shouldn't have been able to do that as they passed through.

They entered the small hall with twenty lifts. John roughly pushed the nearest grille open and stepped into the lift. Sirius joined her.

The door closed and the lift moved up. John stood motionlessly as a disembodied voice called out levels.

They reached level one. John stood with her back against a wall, out of sight to anyone outside the lift. Sirius mirrored her action. John peeked through the opening. Saw no one.

John marched out of the lift. So did Sirius. They jogged down the hall, checking the plaques proclaiming what office was what.

One office door was open a sliver. They could hear a high, cold voice delivering a speech through the crack.

John tip-toed to the door. Sirius crouched at the other side. He peered in.

Several wizards and witches were withering on the ground, their mouths open in silent screams. Others were contorted in unnatural shapes. Yet more others were nothing more than piles of torn flesh.

Two black-robed figures were playing the high, cold voice's speech to a glass megaphone. A dark-haired witch who had deep, hooded eyes and severe cheeks cackled in delight as she pointed her wand at the people screaming in voiceless agony on the floor.

Sirius knew her face: Bellatrix Lestrange.

John burst in and open-fired.

Sirius stayed out. He'd seen what bullets can do—what guns can do. He didn't want to die of friendly fire.

The absolute soundproofing meant Sirius couldn't tell when John stopped without a visual. He braved a look after counting ten.

He almost threw up. The office was riddled with bullet holes and casings. It stank of blood, smoke, and excrement. Blood ran like a river. The two Death Eaters playing the announcement were down and their bodies perforated.

Only two remained standing: John and Bellatrix. John had a bundle of wriggling snakes instead of a gun.

"You filthy blood-traitor, consorting with Muggles, now, are you?" Bellatrix said when she saw Sirius.

"Oh, it's worse," Sirius replied. "I'm the indentured court wizard of a Muggle kingdom, the realm of 221B. I make a living as the Crown Prince's pet dog."

Bellatrix laughed derisively. "A true traitor then! And a slave also! I'll see to it your head is added to the row of elves in Grimmauld Place. It should fit nicely."

The rattle of a cargo hold intruded into their exchange. John had dropped the snakes and taken out another gun from the armoury. Sirius didn't know what kind, but it looked vicious.

Bellatrix giggled long and loud.

"Think you can kill me, Muggle?" she taunted. "I, the Dark Lord's most loyal servant, who was trained by the Dark Lord himself? Do you think you can even touch me?"

John ignored her. Just ripped off the spare clip taped to the gun and slapped it in. Released the safety.

"Would you like to feel pain—real pain?" cooed Bellatrix. She pointed her wand: "Crucio!"

"JOHN, DUCK!" Sirius roared.

John didn't dodge in time. The curse hit her in the chest.

It did nothing. Just scattered into light particles and seeped into John's uniform.

Bellatrix was a picture of astonishment.

"This can't be! Crucio! Crucio! CRUCIO!"

Three beams of red light charged at John like the bullets she'd fired. But before they made contact they dissipated, like windblown sand, and vanished.

It was the most terrifying thing Sirius had ever seen.

Bellatrix must've felt the same, for she screamed with genuine fear:


John ducked and rolled to the side. The killing curse smashed into a wall. Left a crater.

John got up on one knee and fired.

Bella raised a shield but it wasn't enough. The bullet hit her thigh. The impact blew it apart.

Sirius cringed as Bellatrix filled the office with her shrieks of pain.

John stood. Marched over to Bellatrix and loomed over her. Their eyes met. Bella let out an ugly, guttural moan before asking—demanding:

"What are you!?"

Sirius had asked a similar question to Dumbledore when he noticed most magic didn't work on John.

"I have no name for what John is. All I know is John is a Muggle who can absorb magic and impart this ability to the things she touches," was Dumbledore's reply.

"Huh. That explains a lot," Sirius had said. "I lost count the number of chocolate frog cards John touched and rendered kaput. Harry banned her from touching his collection. But if this is the case, why aren't me and Harry drained to nothing?"

"John doesn't absorb the unrealized magic within us," Dumbledore had explained. "But realized magic—spells, jinxes, curses, enchanted objects and the like—these John absorbs. I know not what her limit is."

John, at present, quirked an eyebrow.

"You expect me to f**king answer?"

Bellatrix opened her mouth.

What she meant to say, Sirius was never to know. John shot her in the neck.

A stream of blood shot up like a fountain. It sprayed the ceiling and floor and John's face.

John didn't wipe it off, but continued to glare at the Bellatrix's cooling body.

"Not that kind of f**king movie, bitch," she growled.


Not long after the morning headlines told the wizarding world Corban Yaxley was assassinated, all Magical Mobile phones blasted a message under the Ministry of Magic's header:

"Attention, all true wizards and witches. This is Lord Voldemort speaking to you. By now you know what the Muggles have done to ours and what they mean to do to us. Their intention cannot be clearer: They mean to find us, capture us, and then destroy us.

"Make no mistake. We are about to face the worst witch hunt in Wizarding history. The witch burnings of the medieval period will look a minor event. Even the massacres in Russia and China, the blood fields of Cambodia, will pale in comparison to what is to come.

"Do not think Albus Dumbledore or Harry Potter can save you from this disaster. Who do you think betrayed you? Is it not Dumbledore who sent your precious Potter to live with Muggles? To be trained by them, to be indoctrinated by them, and to ultimately betray us to them when the time came?

"Is it not Dumbledore who brainwashed generation after generation of wizards to accommodate the brutes who hate us? Is it not Dumbledore who weakened us, lulled us into a false sense of security, when all the while he equipped the Muggles with the knowledge that can destroy us?

"Dumbledore has hated us for longer than you know. Look into his history and you will find that his sister died because of magic. That his father died in Azkaban when the Ministry convicted him for harming the boys who contributed to her death. That his mother was killed in a magical accident. When wizard-kind did not give him justice, he swore revenge—the ultimate revenge: the obliteration of everything that took away his loved ones. The obliteration of magic. What you see now is the fruits of his labour.

"There is no turning back. We must conquer or be conquered. Lord Voldemort will not bow to Muggles. Only he can defend you from this threat. He will preserve the Wizarding world and keep it as was meant to be: Pure and True. He will—"

The announcement cut off right there.

While the Wizarding world at large puzzled over the abrupt stop while fearing its message, in Hogwarts, Grandmaster Shin rose to his feet.

"What a load of rubbish," he thundered inside the Great Hall, for everyone to hear. "Voldemort alone can defend us? He is the reason why Muggles feel the need to fight. Conquer or be conquered is the only option? Psh."

Shin lay a hand on Mrs Jacqueline's shoulder.

"Don't you know what my daughter is capable of?"


In a town called Hemel Hempstead, the International Confederation of Wizards was holding an emergency session.

"Ladies and Gentlemen, I called for this meeting so that we may discuss the recent, unprecedented threat to our existence," Supreme Mugwump Dumbledore began. "I am also aware that you may have reasons to doubt me. After this is over, I will, of course, submit to anything you deem fit … whether it is an investigation or a demand for my resignation."

There was a murmur among the delegates, but no one outright questioned Dumbledore's right to speak.

"As you have all undoubtedly heard, an individual— or several individuals— used a Muggle weapon to kill three known Death Eaters and a high-ranking official in the British Ministry of Magic, one Corban Yaxley," Dumbledore said. "It is not certain if the two incidents are related. But we believe Yaxley was assassinated. The killing was too professional, and the target too strategic, to be anything else.

"While I hope and pray these are isolated incidents, I have reasons to believe this is not the case."

"We found soldiers from the Muggle army surrounding magic villages with those ridiculous contraptions they use to flatten hills," reported the Chinese representative. "Some were Squibs who joined the Revolution."

"Muggle law enforcement arrested sixty wizard intellectuals in my country last month," said the rep from Russia.

The representatives from South America chimed in. Their stories were similar: the sudden appearance of Muggle militia in close proximity to magic settlements and a surge in witch or wizard arrests. Harassment.

"This is a declaration of war!" the US representative shouted. "The Muggles are showing us what they can do!"

"The global nature of these incidents does not bid well for us, to be sure," Dumbledore said. "The question is this: How should we respond? If we do this wrong, tensions will only escalate. Considering the state of our world and the threat that's brewing within it, a war between Muggles and Wizards is the last thing we want."

"You speak of 'Ee-Who-Must-Not-Be-Named," said the French delegate.

"Yes, I speak of Voldemort," Dumbledore confirmed, inciting horrified noises from many. "We can discuss him in a different session. For now, let us focus on how to mend the biggest breach in the Statute of Secrecy."

"Agreed," said the Swedish representative.

Dumbledore nodded at her before moving on.

"We must first ask: How did we come to this point? Since the establishment of the Statute of Secrecy in 1692, we wizards have relied on anti-Muggle jinxes to fool Muggle minds and memory charms to make Muggles forget any magical occurrence they've witnessed. These have served us well enough. Until now.

"Now, Muggles no longer trust their own memories and senses. It is common knowledge among self-aware Muggles that the human mind misremembers and forgets— on its own and without the benefit of magic. Muggles are also aware their senses can betray them. To counteract their self-doubt, they've created devices that can record events and remember them longer and more accurately than human memory ever can. They also created sensors that correctly measure and interpret the world around them. These devices are now so prevalent and so cheap, you will be hard pressed to encounter a Muggle who doesn't have one."

"So memory charms are becoming obsolete?" asked the Brazilian representative.

"Yes, I believe that to be so," Dumbledore answered.

"But that is not all," one of the African representatives noted.

Dumbledore shook his head. "No. If Muggles merely improved their sensing and recording capabilities, we need not worry too much. The problem is Muggles have also improved their ability to share this information. They have a new medium called 'Internet' which allows one to share photographs and videos and other information to millions, if not billions, of people all around the world within sub-seconds. I've dabbled with it a little myself, and it is not an exaggeration to say news now travel at the speed of light. For a person who was born when Muggles were still using horse-drawn carriages, this was overwhelming, to say the least.

"Anyway, this disturbing ease of information sharing will make it virtually impossible to remove information once it is published. There is already an axiom that states: once it is on the Internet it stays on the Internet forever."

Dumbledore swept his gaze over everyone.

"I need not belabour how unprepared we are to face this new medium."

"This is a disaster," muttered the German representative.

There was a moment of heavy, meaningful silence.

"So, the recent threat stems from cheap and readily available sensing and recording devices and the Muggles' improved ability to share information," the African representative from before observed. "It stands to reason, then, our response must target these two things, particularly the latter."

"Very well put, representative Akingbade," Dumbledore said. "For this reason, I invited a Muggle Technology Subject Matter Expert. Ladies and Gentlemen, I give you Mrs Jacqueline Shin Ransom, founder and majority shareholder of the Magical Mobile Network."

Dumbledore stepped aside and let a small young woman take the podium. She gave the impression of a fragile bird that had no business leaving the sanctuary it lived in. Yet when she regarded her audience of prestigious wizards and witches, her expression was firm and resolute.

"Dear members of the International Confederation of Wizards," said Jacqueline in a soft, clear voice. "I want you to know if the solution I present to you today is used to its fullest extent, it has the potential to destroy six billion Muggle lives."

Jacqueline drew in a shaky breath as her audience broke into wild whispers, gasps and mutters of disbelief. When they quieted down, she continued:

"Therefore, I need your solemn vow, sworn upon your magic, that you will never use it against them after this one time…"


On New Year's Eve, the Internet and all wireless telecommunication went down for an hour. The ensuing panic was epoch-making.

The same day, for thirty solid minutes, major banks couldn't access their IT systems, household name tech companies discovered entire floors of servers had gone missing from their data centres, and government agencies found their most sensitive and mission-critical data had vanished wholesale. Only for everything to be restored as if by magic.

At night, before the calendar turned, the electric grids of all major world powers surged and sputtered, making city lights blinker on and off. If anyone analysed the pattern— and a certain British civil servant certainly did— they would've read the message encoded in it:

don't you dare

Final Notes: It's bittersweet to cover the Marriage Story after withholding it for so long. And it's still not the full chronology. One day, dear readers. One day.

For those who have trouble imagining ASIM!John, I've posted a sketch on my blog (titled postmortem): booksofchange dot com / blog

Coming up with first names for Death Eaters was hard. Bellatrix vs. John was my favorite part to write. Most bloodthirsty, too.

Babajide Akingbade is the African representative and the Supreme Mugwump after Dumbledore, according to Pottermore.

Math detail: How did Jacqueline come up with 6 Billion?

World population in 2015: 7.2 B
Those who are off-grid in 2015: 1.1B
Therefore, the total potential affected: 6.1 Billion

I'm giving out the expanded version of A Study In Magic, Year One, to those who join the email list ... now available in ePub and Kindle format. Once I mark this story complete, I'll be sending out ebook (Kindle and ePub) versions of ASIM to all subscribers. You should find the signup form on the blog page and the story page. There is a slide-up form, too.

Cheers, BOC
booksofchange dot com