Carry On | A BBC Sherlock Fanfic

Compromised

The large open-plan apartment was cast in shadow. The feeble light from streetlamps and neighbouring buildings barely pulled it from the brink of complete darkness, despite the large windows stretching across one wall. On an adjacent wall was the entrance to the apartment, an imposing slate door. The handle rattled. There was a pause, then four quick beeps sounded as someone punched numbers into the keypad just outside. A trill announced the correct code had been entered. The door swung open, letting in a beam of white light that was broken by the form of a man with a long coat and wild hair.

Sherlock Holmes drifted soundlessly into the apartment. The door swung shut behind him, plunging the place into darkness again. His eyes were quick to adjust. To his left was a neat arrangement of cuboidal couches around a marble coffee table, all backlit by the windows. To his right the plush carpet gave way to a hardwood floor as the room transitioned into a spacious kitchen and dining area. Sherlock scanned everything from the magazines by the sofas to an empty takeout box on the dining table, left there for more than a day. He gritted his teeth when he spotted an empty slit in the wooden knife block on an otherwise immaculate worktop. A missing knife.

He slipped another knife out of the block, concealed it in his sleeve, and stalked towards the bedroom.

The metallic smell of blood permeated the bedroom air. Sherlock flicked the light switch. White light glared down at the body of Charlie Mundungus laying supine atop his bed, highlighting his blood-spattered chest. The missing knife protruded from the pool of red like an unholy flag. Approaching silently, Sherlock assessed the body. No signs of struggle. He was killed in his sleep. Died at least 12 hours ago.

A note was stuck between the kife's hilt and the flesh it was embedded in. Though blood-soaked, the black writing on it was legible. Sherlock loomed over it and his piercing gaze fell on the text. It read: "Haha, you thought!"

Yes. Sherlock thought. He thought there was still a chance that the burnt corpse had been Mundungus's, not John's. (Don't think about him—about how he—that he's truly—just don't.) And he thought Mundungus had left his apartment and that he and John were following him to the warehouse.

He thought wrong.

False intel. The homeless network was compromised.

The realisation sent his thoughts spiralling with dire implications, but with the sound of his pocket magnifier snapping open, he refocussed. He fell into his detective routine (trying not to think of the half that was missing from it) and did an extensive inspection of the crime scene, leaving no crease, fingernail or fleck of blood unexplored. Then, Sherlock removed and bagged the note. The weapon was left as is; he knew a criminal of this calibre wouldn't leave prints. But the note—now that was the equivalent to a window into the murderer's mind, and something he could dig clues out of in a lab.

First, however, Sherlock had to find the rot that had wormed its way into the network, and gouge it out.

-

"Margaret." The detective's cold voice permeated the still air and drew the reluctant attention of the homeless woman. They were in front of a building just opposite Mundungus's apartment. A blanket of fog floated about them, clinging to the pavement it had been swept onto by the occasional car, and dimly glowing like sulfurous fumes under the amber streetlamps' glare.

"Mr Holmes?" Margaret asked with open confusion as she unbundled herself from her ragged blanket.

"Yesterday, did you notify me that Mundungus left his apartment?"

"No," she replied, unphased by his directness, "he's been in all day."

"Your phone." Sherlock held out a hand. Reaching into the ratty folds of fabric encasing her, she fished out the phone and handed it over. 

As Sherlock rifled through its contents, a crease formed between his brows. "We've been hacked," he concluded through gritted teeth.

"They made it look like I notified you?"

"Yes."

"Must be a bloody smart computer-wiz."

"It would take one to break into an isolated local network, let alone mine, but that's not—" He breathed out roughly. He was pacing now, letting his thoughts tumble from his lips. "It's not the worst of it. This someone had to uncover the network itself, a network no criminal, not even the police have any inkling of. This person was smart enough to find it."

"Or determined enough," Margaret supplied grimly, bringing the other's pacing to a halt.

"Yes," Sherlock huffed, his breath clouding around his face like a plume of dragon flame. His eyes held fire. There was work to do. 

He handed the phone back to Margaret with a £50 note pressed against it. "Consider the network offline, indefinitely."

There was a deep sadness in her eyes as she gazed up at him. "It's been an honour, Mr Holmes," she said. He tipped his head at her distractedly, a sleek black government car swerving into the distant street corner grabbing his focus. 

In the few seconds it took for Mycroft to pull up in front of Mundungus's apartment building, Sherlock had vanished into the night.