Chapter 3: The Interrogation
The message from M came not twenty-four hours after the library encounter, brief and irrevocable as a surgical incision.
M: The Diogenes Club. Nine tonight. Use the keycard. It has been reactivated.
Jill stared at the words, the memory of Sherlock’s dissecting gaze still fresh. Her fingers, stained with methylene blue from a morning spent highlighting cellular structures, felt clumsy against the screen. She wanted to refuse. To throw the phone against the wall and bury herself in the clean, predictable logic of Gray’s Anatomy. But the bluish-grey clay from Russell Square was still a faint smear on her boot heel, a tiny, damning piece of evidence that connected her to something real. Mycroft knew it. He would expect her.
At 8:55, the same silent car collected her. The city streamed past, a river of light and shadow. This time, when the doorman nodded, she gave a tight nod back, a pathetic mimicry of composure. Her heart was a trapped bird against her ribs.
The Diogenes Room felt different at night. The fire was higher, casting darting, hungry shadows up the book-lined walls. The silence was thicker, a living thing pressed against her eardrums. Mycroft was in the same oxblood chair, but he wasn’t reading. He was simply waiting, his hands resting on the arms of the chair, his gray eyes fixed on the doorway as she entered.
“Sit,” he said. No greeting. No prelude.
She sat, her body rigid. On the small table between the chairs was a single, slim folder, beige and unmarked.
“Recount the encounter at the medical library. From the moment you became aware of his presence. Omit nothing. Filter nothing. Include your own sensory impressions and internal monologue.”
His voice was flat, a recording device given human form. This wasn’t a conversation; it was an extraction.
She took a breath. “I was upstairs on the mezzanine. Writing an essay. I heard a commotion at the entrance—a security guard, Keith, and… a voice.”
“Describe the auditory quality.”
“Loud. Clear. Impatient. A baritone, but… vibrant. It carried.” She closed her eyes, summoning the scene. “He said, ‘It is a requisite piece of evidence in an ongoing investigation. The chemical residue must be cross-referenced with your archival periodicals on toxic moulds. Stand aside.’”
“Accurate,” Mycroft murmured, as if checking a box. “Continue.”
She described Sherlock’s appearance—the rain-slicked coat, the wild curls, the evidence bag with the plaster. She detailed Keith’s bewilderment, Sherlock’s brusque compromise about the journals and tea.
“His posture?”
“Agitated. He paced. A tight circle. His energy was… contained but intense. Like a wire humming.”
“His eyes. Where did his attention go?”
“He scanned the room. It was quick. Comprehensive.” She hesitated, the memory of his gaze locking onto hers sending a fresh chill through her. “He saw me. For a second. Looking down from the railing.”
Mycroft’s eyes sharpened. “Describe his reaction.”
“There wasn’t one. Not really. It was… an assessment. A cataloguing. Then dismissal. I was a data point filed away. Female. Student. No threat.” The words sounded clinical, even to her. She was describing herself as a specimen.
“And then?”
She explained her deliberate descent, the water bottle, the calculated drop. “He heard the noise. Looked at me. Then at my shoes.”
“His exact words.”
“‘Your shoes.’” Jill’s voice tightened. “‘Traces of three different types of clay-based mud. London street silt, the distinctive orange terracotta dust from the construction near Paddington Station, and a bluish-grey, chalk-heavy clay found predominantly in the manicured flowerbeds of… Russell Square Gardens. Your route today was convoluted. Erratic. Either you are profoundly lost, or you were following someone. Which is it?’”
A flicker of something—approval?—passed over Mycroft’s face. “His deduction was accurate, but his conclusion flawed. You corroborated the flawed conclusion.”
“I said I was lost. A confused first-year.”
“And his response?”
“A dismissive sound. ‘Hmm. The cognitive map of the average student is notoriously unreliable.’ Then he turned away. He was done with me.”
For a long moment, Mycroft was silent. The only sound was the crackle and pop of the apple logs in the fireplace. He leaned forward, his presence suddenly dominating the space between them. “Now. The phone call with Lestrade. You mentioned arsenic. Scheele’s Green. The historian husband. Repeat everything you heard. Inflection. Cadence.”
Jill faltered. She had given the facts in her text, but this demand for performance, for nuance, felt invasive. “‘Of course it’s arsenic-based, Lestrade.’” She tried to mimic the rapid, confident cadence. “‘The green hue in the bedroom wasn’t aesthetic choice, it was Scheele’s Green pigment. The wallpaper. The spores from the damp plaster are just the delivery system. The husband is a historian specializing in Victorian domestic life? Pathetically obvious.’”
She paused, searching for the next fragment. Her mind, tired from a day of studies, went blank. “He said something else… about the mould. The specific type…”
“What.” Mycroft’s voice wasn’t louder. It was harder. A diamond-tipped drill.
“I… I can’t recall. It was just a name. A scientific name.” She shook her head, frustration bubbling up. “It wasn’t important. The point was the method, the husband—”
“Nothing is unimportant.” His words were ice. “A name is a key. A specificity is a thread. Pull it, and a network unravels. You have a medical student’s mind. Train it. Access the sensory memory. What did you hear?”
She stared into the fire, trying to wrestle the ghost of the sound from the air of the library. The hum of study lamps, the rustle of pages, his voice…
“I… I think it started with an ‘A’. Asper… Aspergillus? No. That’s common. This was different. Archaic.”
She felt him move before she saw it. His hand, which had been resting on his own chair arm, shot across the small gap between them. His fingers, strong and startlingly warm, clamped around her thigh just above her knee. The grip wasn’t violent, but it was immovable. A lock.
Her breath hitched. Every thought emptied. Her world narrowed to the pressure of that hand through the fabric of her jeans.
“Do not think,” he hissed, his face now closer, his gray eyes consuming her field of vision. “Think, and you edit. You filter. You judge the value of the memory. Access it. You were there. The sound entered your ear. Retrieve it.”
Panic and humiliation warred in her chest. She wanted to shove him away, to bolt from the room. But his gaze held her pinned more effectively than his hand. This was the test. Not the library. This.
She stopped fighting. Stopped trying to remember. She let herself fall back into the moment. The chill of the dropped water bottle in her hand. The smell of old paper and dust. The way his voice had bounced off the marble foyer floor.
“Stachybotrys,” she whispered, the word emerging whole from the dark. “He said ‘Stachybotrys.’ But not like that. He said… ‘the Stachybotrys atra is merely the carrier, Lestrade. The poison is in the pigment.’” She looked at him, the full sentence returning. “That was it.”
His fingers loosened. He leaned back, releasing her. The imprint of his grip burned on her skin.
“Stachybotrys atra,” he repeated softly. He didn’t thank her. He made a note, mentally. “A toxic black mould often found in water-damaged historical buildings. Consistent. Good.”
The ‘good’ felt like a slap. She rubbed her thigh, the sensation of his touch lingering, a brand of complicity.
“You manipulated the encounter,” he stated, reopening the folder on the table. It contained a single photograph, taken from a high angle—the library foyer. There she was, a small figure bending for her bottle. Sherlock was a blurred shape of dark coat facing her. “You engineered the drop. You provided a plausible, submissive explanation for your presence. You performed ‘normalcy’ adequately.”
“You told me to be normal,” she said, her voice low and tight.
“I did. And you obeyed. The question is, did he believe it?” Mycroft tapped the photograph. “His dismissal was theatrical. Over-performed. Sherlock is rarely so… generically contemptuous. His insults are typically more creative. More personalized. The ‘cognitive map’ line is a stock phrase he uses for genuinely tedious people. You, Miss Tallentire, sparked a deduction about your route. That intrigued him, if only for a moment. Your subsequent performance of clumsiness and confusion may have been a shade too complete.”
“You’re saying he saw through it?”
“I am saying he may have registered a minor anomaly. A flicker of discordance between the girl with the observably complex route and the girl who flusters over a dropped bottle. He chose, for now, to ignore it. But the seed is planted. He has filed you not as ‘student, anonymous’ but as ‘student, potentially curious.’ A upgrade in his mental index.”
Jill felt sick. “What does that mean?”
“It means your utility may be greater than I initially projected. And your risk profile is marginally elevated.” He closed the folder. “You will continue. Your next assignment is proximity. You will find a reason to frequent the vicinity of 221B Baker Street. A coffee shop. A part-time job. A study group in the park. You will become a familiar, unremarkable fixture. You will observe comings and goings. Specifically, you will note anyone else observing them.”
“You want me to watch his watchers.”
“I want you to be a mirror. Your presence, if noticed by hostile parties, will give them pause. They will wonder who you are. They will, perhaps, make a move to ascertain your loyalties. That move will reveal them.” He stood, smoothing his jacket. The meeting was over. “The primer I provided has a section on passive reconnaissance. Re-read it. Your keycard will grant you access to this room for the next month. Use it if you feel compromised. A car will be available.”
“And if someone approaches me? One of these ‘hostile parties’?”
Mycroft walked to the fireplace, his back to her. The flames painted his silhouette in shifting orange and black. “Then you will have your first practical lesson in fieldcraft. Do not engage. Do not attempt to dissemble. You are a medical student. You are naive. You are, above all, forgettable. You will report the contact immediately.”
Forgettable. The word stung more than the grip on her thigh.
He turned, his expression unreadable. “Your reaction to pressure is… better than expected. The memory retrieval was satisfactory. The emotional response,” his glance flicked to where his hand had been, “is a liability. Control it.”
He left then, without another word, a door in the panelled wall she hadn’t noticed swinging shut behind him, leaving her alone with the fire and the ghosts of her own fear.
Jill sat for a long time, watching the flames devour the logs. The burning sensation on her thigh faded, leaving a deeper, colder ache in its place. She thought of Sherlock’s brilliant, dismissive eyes. She thought of Mycroft’s calculated, invasive touch. She was a tool between them, being assessed for its durability and its sharpness.
Finally, she stood. Her legs held. She walked out of the Diogenes Club, past the silent doorman, into the London night. The air was cool, a relief. She started walking, with no direction.
On a whim, she turned her steps north, weaving through the crowds. It took her forty minutes, her mind blissfully numb from the rhythm of walking. She found herself standing across the street from a familiar, unassuming facade. 221B Baker Street.
The flat was dark. No silhouette in the window. Just the warm glow of a streetlamp on the black door and the brass knocker.
She stood there, a stranger in the shadows, and practised seeing. She noted the woman walking a small dog, pausing unnecessarily to tie a shoelace. She saw the delivery van double-parked halfway down the block, its engine off. She watched a man in a dark jacket lean against a railing, scrolling on his phone, his eyes lifting every thirty seconds to glance at the famous door.
A mirror. A canary. A thread.
She turned and walked away, her ordinary boots silent on the pavement, every sense screaming.
The walk back to her dorm was a blur of fragmented observations—a cyclist’s tire hissing on wet asphalt, the too-sweet scent of candy floss from a closed stall, the distant wail of an ambulance that made her think of arterial bleeding and response times. Each detail felt like a potential clue in a case she hadn’t chosen. Her thigh still throbbed with a phantom pressure.
Sarah was boiling pasta when Jill pushed open their door. “You look like you’ve seen a cadaver that sat up and asked for the time,” Sarah said, stirring the pot.
“Just a long day,” Jill mumbled, dumping her bag. The normalcy of the scene—the steam, the clang of a spoon, Sarah’s mismatched socks—felt like a fragile diorama.
“Well, shake it off. I need a favor.” Sarah pointed a dripping wooden spoon at her. “The café on North Gower Street, by the BBC? They’re hiring part-time. I told the manager I knew a smart, presentable human who wouldn’t burn the place down. Interview’s tomorrow at ten.”
Jill froze, a bottle of water halfway to her lips. North Gower Street was a seven-minute walk from 221B Baker Street.
“You told her what?” Jill’s voice sounded thin.
“That you’re a tragically poor medical student in need of cash. Which is true. What’s the problem?” Sarah turned, her expression shifting. “Hold on. Is this about that weird keycard thing? Or that posh bloke in the car? Jill, what’s actually going on?”
The concern in her friend’s voice was a tangible warmth. Jill could have leaned into it, confessed the fear, the coercion, the burning imprint of a hand on her leg. She wanted to. The words piled behind her teeth.
“Nothing. It’s nothing. Just... family stuff. Money stuff.” The lie tasted like ash. “An interview’s perfect. Thanks, Sarah.”
Sarah eyed her for a long beat, then shrugged. “Okay. But if you’re running drugs, I get a cut for being your reference.”
The laugh Jill forced out was too sharp, but it sealed the subject. She spent the evening staring at her ‘Principles of Peripheral Awareness’ primer, the words swimming. Establish a natural cover. Integrate. Do not force proximity. Mycroft’s assignment and Sarah’s suggestion had collided with a sickening symmetry. It felt less like an opportunity and more like a trap snapping shut.
The interview the next morning was a study in surreal dissonance. The café, ‘The Speckled Hen,’ was all exposed brick and the rich, comforting smell of roasted beans. The manager, Donna, was a friendly woman with flour in her hair and a no-nonsense handshake.
“So, Sarah says you’re a medic. Brutal hours. Can you handle closing shifts? We do a lot of trade with the production folks from the BBC down the road. They’re drama,” she said, rolling her eyes fondly.
“I’m good with brutal,” Jill heard herself say. She was. She made a joke about surviving on caffeine. She smiled. She was, she realized, performing ‘normal, hireable Jill’ with the same focused detachment she’d used to perform ‘confused student’ for Sherlock.
She got the job. Her first shift was that Friday evening.
Her phone buzzed as she left the café. M: Adequate. Report anomalies.
He knew. Of course he knew. The city felt like a circuit board, and she was a newly soldered connection, glowing faintly under his microscope.
Friday evening descended prematurely, a damp gauze of fog clinging to the streets. The Speckled Hen hummed with pre-theatre bustle. Jill learned the espresso machine, her hands moving automatically, while her eyes tracked the world outside the window. From her position at the till, she had a clear view down the street toward the intersection that led to Baker Street.
She served cappuccinos and sourdough toast, her smile a fixed, professional mask. Her mind, however, was a rotating catalog of the street: the same Nissan Micra circling the block twice, the courier who lingered too long smoking outside the pharmacy, the woman with the large shopping bag who never seemed to shop.
Then, at just past eight, he appeared.
Sherlock Holmes was a streak of black wool and velocity, his coat billowing behind him like a storm cloud. He was speaking into his phone, his face a mask of intense irritation. He strode past the café window without a glance, heading north.
A minute later, a man in a beige trench coat—older, with a tired, kind face—hurried past in the same direction, muttering into his own phone. “Yes, I’m on him, Mrs. Hudson. He’s heading toward the park. No, he hasn’t eaten.”
Jill’s pulse skipped. This was it. The ‘comings and goings.’ She wiped the counter with a rag, her gaze glued to the street.
Five minutes passed. The Nissan Micra completed a third loop. The woman with the shopping bag finally entered the pharmacy.
Then Sherlock stormed back into view, this time heading south toward Baker Street. He was alone. His expression was different now—triumphant, razor-sharp. He held a small, clear evidence bag pinched between his thumb and forefinger. Something dark and feathery was inside.
As he passed the café, his head turned. His sharp eyes scanned the interior, a hunter’s sweep. They passed over her, registered the green apron, the queue of customers, the steam wand hissing. For a nanosecond, they locked onto hers.
There was no recognition. Just a flicker of assessment—barista, female, busy—before his gaze snapped forward, already fixed on his next thought. He vanished down the street.
The breath Jill had been holding leaked out of her. He hadn’t seen her. Or he had, and she was, as Mycroft intended, furniture.
Her shift ended at eleven. The fog had thickened, muffling sound and shrinking the world to haloed streetlights and the soft scrape of her own footsteps. She turned toward Baker Street, not directly, but on a parallel road, her new commute a convenient detour.
The blue plaque of 221B was just visible through the gloom. The windows were lit now, a warm yellow rectangle in the dark façade. A shadow—tall, thin—paced rapidly across the ceiling.
As she watched, another shadow joined it, shorter, rounder-headed. The second shadow gestured wildly, then seemed to throw up its hands. A faint, raised voice, muffled by glass and distance, reached her: “…not a basket, Sherlock, it’s a spectimen jar! You can’t just leave it on the kitchen table!”
A deeper, calmer voice rumbled a reply she couldn’t catch.
Jill allowed herself a small, exhausted smile. It was bizarrely ordinary. A flatmate argument. For a moment, the legendary Sherlock Holmes was just a man annoying his friend by leaving dead things on the furniture.
She was about to turn away when a van, painted a matte, non-reflective gray, rolled slowly down Baker Street. It had no markings. Its headlights were off. It crawled past 221B, almost stopping, then continued around the corner.
It didn’t belong. Not in a residential street at this hour. Not with its lights off.
Her phone felt heavy in her pocket. Report anomalies. This was one. But a van driving by? It could be nothing. A lost driver. A cautious lover.
The front door of 221B burst open. Sherlock stood silhouetted in the light, his voice clear and angry in the quiet street. “Lestrade! The footprint cast is a reproduction! The museum gift shop sells them as paperweights!”
The door slammed shut.
The gray van, now idling just around the corner, suddenly roared to life. Its tires squealed as it accelerated away, the sound swallowed by the fog.
Jill stood frozen on the pavement. The van had been watching. It had fled at the sudden activity, the raised voice. That wasn’t nothing.
Her fingers were cold as she pulled out her phone. She typed, her thumbs clumsy with adrenaline.
Sighting. Gray unmarked van, no lights, conducting slow pass of 221B at 23:12. Driver observed. Vehicle fled upon subject’s emergence from property. Possible surveillance.
She sent it. The message status changed to ‘Delivered.’
Thirty seconds later, her screen lit up. Not a text. An incoming call. The ID simply read: M.
The ringtone was shockingly loud in the fog-quiet street. It vibrated in her palm, a demanding pulse. He never called.
She swiped to answer, bringing the phone to her ear. She didn’t speak.
“Stay where you are.” Mycroft’s voice was stripped of its usual dry polish. It was cold, operational steel. “Do not move. Do not react. A car is sixty seconds away. It will take you to a secure location. The van has been tracked. You are now a person of interest.”
The line went dead.
Jill lowered the phone. The fog curled around her, suddenly feeling less like mist and more like a shroud. She was no longer a mirror, or a canary.
She was bait. And something had just taken the hook.