The metallic thud of the heavy deadbolt reverberated through the empty café as Irina secured it into place. She turned to inspect the windows, where layered blackout fabric obscured the street beyond.

  Nightlights illuminated trailing pothos vines casting intricate shadows from their perches in gutted electronic casings. A row of silent terminals stood with their curved monitors dark, while the server rack behind the bar emitting its constant hum—digital hearts beating at idle.

  Their new “secure facility”—the café's back room—awaited scrutiny. Tightly woven chicken wire covered every centimetre of wall and ceiling, forming an effective electromagnetic barrier. Countless tests, Irina assured them, performed with a hand-wound ferrite-loop connected to a Gorbushka-sourced oscilloscope saw to that.

  “No visitors tonight.” With a flourish, Irina cut the exterior lights, her hand moving across the brass switchboard to verify each unnecessary circuit's disconnection.

  Katya positioned the Pentagon 128 on the insulated worktable. The Soviet ГОСТ enclosure—military spec, repurposed from signal processing equipment—reflected dim light from a CRT, glass behind fine copper mesh salvaged from an industrial microwave. Each cable bore multiple wrappings of conductive tape, ruthlessly trimmed and shortened—the preferred method of electricians who nursed grudges against radio frequencies.

  “Power regulation checks out.” Katya tightened screws with three sharp twists. “ROM chips pristine. Isolation protocols in place. We're even injecting random clock cycle skew in case anyone with a spectrograph has too much spare time.”

  A coiled length of CAT-5 cable lay abandoned on the floor, serpentine and suspect. Irina plucked it between two fingers like a biohazard. “Absolutely not.” The cable landed in the outside skip with a muted thump, barely penetrating their sealed sanctuary.

  In the corner of the newly secured inner sanctum stood a well-used Robotron printer, its mesh-wrapped cable ensuring complete digital isolation. “Serial debug output,” Irina announced, patting its dented housing. “NSA-approved by accident. Whatever executes on the Pentagon, we get an audit trail here.”

  Vitya's eyebrow lifted at the extensive precautions, amusement playing at his lips. “And the noise?”

  Irina gestured to the walls. Behind the wire mesh, a regular lattice of foam pyramids: Sound dampening.

  The café space belonged to them now, three figures bathed in the glow of indicator lights. Their workspace had transformed into an eccentric fortress, born from engineering rigour and paranoid innovation.

  Vitya studied the unlabelled disk between his fingers, turning it over as if its plastic casing might reveal some clue about its origins. The stranger's words at the demo party echoed in his mind: “Your mother… she would be proud.” A calculated phrase that struck too close to home.

  “Remember.” Katya hovered near the manual kill switch. “Any network request means immediate shutdown.”

  “Relax,” Irina murmured, eyeing the grounding points. “There's not even a carrier pigeon getting a signal out of this place tonight.”

  The drive slot seized Vitya's diskette with a sharp click, loud against their dampened environment. The Pentagon's screen lit up, displaying nothing but a cursor—no auto-execution, just empty possibility.

  Scanning the disk contents, Vitya discovered a single executable: “ВН_ИГРА” (“war game”), surrounded by numbered data files.

  “Interesting.” His scrutiny fell upon file sizes and timestamps. “Creation dates conflict with the disk format”—unmistakable evidence of manipulation.

  He looked to Katya and Irina. They nodded, understanding the significance. Vitya typed the command to execute the programme. The printer began to chatter.

  The screen flickered, displaying a menu of exchange numbers—Moscow exchanges, some long decommissioned.

  “Try the Khamovniki exchange,” Katya suggested, leaning closer.

  Vitya selected the number. The Pentagon emitted a convincing series of connection tones, including the distinctive click pattern of a retrofitted exchange.

  A new console: a PBX management shell, complete with the hash prompt of imported Alcatel systems. The printer clattered continuously.

  “It's simulating a full exchange environment,” Vitya murmured, typing a diagnostic command. The echo delay following each keypress surprised him. “Artificial latency. Mimicking dial-up round trip.”

  “This isn't contemporary,” Katya said, examining the routing tables. “It's a replica of Khamovniki's exchange as it existed in 1998.”

  Irina traced a finger along the edge of the circuit board, brow furrowing. “Most state outfits would've left tool-marks. FSB loves a brute-force approach—detain first, debug later.”

  Vitya's mind wandered to memories of military comms, hastily-patched software, burnt insulation and dry solder joints after rushed inspections. “Signals can barely keep the radio logs straight, never mind… this.” He nodded at the Pentagon.

  Katya studied the exchange shell on the monitor, lips pressed thin. “This isn't just Western tech—somebody mapped out our quirks down to the last mis-wired relay.”

  A silent pause. The printer rattled on, indifferent.

  Vitya tapped the desk, gaze fixed on the debug stream. “Whoever did this gets both worlds. They're not just funded. They know exactly where we're vulnerable—and what we'd overlook.”

  “That takes more than clearance.” Irina's mouth twisted, as if tasting the word. “Someone who can move between worlds.”

  Katya turned back and probed at the shell. Each keystroke intended to examine but not trigger. The display flickered with encrypted traffic. A puzzle with perilous implications.

  She paused. “We can't attack this head on. This dial-up just doesn't give us enough access. It's a garden path.”

  The phrase hit Vitya. Garden paths—elegant traps designed to lead the unwary down predictable routes. His conscription notice flashed in his mind: another garden path, perhaps?

  Irina leaned against the table edge, amber light catching her Spectrum ULA pendant. “Perhaps we need a useful idiot.”

  The café door lock clicked. Vitya tensed, then recognized Azamat's silhouette. The Kyrgyz trader balanced four steaming cups, weaving between dormant terminals.

  “I hope you didn't mean me!” Azamat grinned, setting the tea down with surprising delicacy. The scent of bergamot cut through the electronic musk.

  Vitya accepted a cup. Another hour on the tally counting since he'd slept properly. No way to receive messages from the relief carer inside this Faraday cage. He'd need to step outside soon.

  From his messenger bag, Azamat produced a thick bundle of continuous printer paper—green-barred fan-fold. A cascade of memories triggered: his mother's office at Arsenal, dot-matrix rhythm, allocation tables.

  “PBX vulnerabilities,” Azamat announced, spreading the documentation across the table. His accent thickened with excitement. “3com, Fujitsu, Siemens, Ericsson, Cisco—you name it, we got it.”

  Katya looked up from the screen, possibilities already visibly forming behind her eyes.

  “Present from my dorm-mate at MIPT. Digital for physical.” A chuckle escaped his lips. “I promised to stop bugging him about the two optoisolator boards he ‘borrowed’.”

  Katya and Irina leaned in over the printout, flipping through exploits in tight synchrony—buffer overflows, bypasses, each vulnerability passing rapidly beneath their fingertips. Silent glances and brief nods sufficed; they hunted for a weak link.

  Irina's hand stopped. “Use-after-free in that Cisco exchange from 1995.” Her Dublin accent surfaced as excitement overtook her careful Russian. “If that works, it's pretty much open season.”

  Vitya gauged the implications. With control over the Cisco PBX, they could examine the target exchange undetected—like disarming a bomb after removing its detonator. His attention turned to the printer, still capturing every byte. His mother's old advice: Always maintain documentation of system states before modification.

  If you discover this tale on Amazon, be aware that it has been unlawfully taken from Royal Road. Please report it.

  Katya's fingers danced, plotting the steps to pry open the Cisco vulnerability. From command line choreography, she assembled an electronic skeleton key.

  The monitor filled with terse sequences, meaningless on their face. Instructions crafted to push values into a buffer that the router code believed it alone controlled. Tricking it into doing Katya's bidding. Elegant. Exploiting the gap between system perception and hardware truth.

  “Azamat, your friend doesn't validate his exploits,” Katya muttered, adjusting values. “Off-by-ones everywhere.”

  Vitya spotted the errors too. The documentation was full of arithmetic slips—deliberate, maybe.

  Azamat grinned, catching the light. “Safer to be thought incompetent than dangerous.”

  A truth Vitya recognized; he too hid efficiency in his public code and kept optimizations in shadow. A survival tactic.

  Irina leaned over Katya's shoulder. “The general idea's sound. We can work with this.” Katya shifted to allow Irina access to the keyboard. Her commands landed with deadly accuracy—bringing to bear the digital lock-pick fashioned from Azamat's notes.

  “Try hopping on to Perovo exchange next,” Vitya said. “It handles government traffic off-hours.”

  Irina nodded, never breaking rhythm. The suburban exchange now under her command yielded access to bench-marking tools that could be used to scrutinize Perovo's traffic.

  Vitya filled his notebook with hexadecimal sequences, each representing timing intervals. A timing diagram took shape under his pencil. Like a constellation, a pattern emerged. Not random—engineered.

  “The timing signatures are consistent,” he said, circling the pattern. “Each destination creates a unique delay.”

  The oracle attack in full flow, the technique discussed as a hypothetical during his year at the 54th Electronic Intelligence Regiment—intelligence gathering for deployment against foreign embassies. Seeing it applied against civilian infrastructure felt different. Real. Dangerous.

  Vitya focused on the numbers. Pattern-matching as he did for music synchronization and raster timing. Each interval matched: a correlation no encryption could hide.

  Irina snapped her fingers, pointing at the bench-marking output.

  “There.”

  Vitya saw it too. His pencil attacked the page, grouping related timings with neat boxes.

  “Routing signature matches recipient. Millisecond variations across sequential hops form a fingerprint for each connection.”

  “We have a proof of concept,” Irina said. “Routing time reveals the recipient. This is a nasty simulation.”

  Vitya felt the cold settle inside. “Whoever built this has broken the real thing. Side-channel attacks…” Memories of classified briefs. “In SIGINT, we saw prototypes, but this is next level. They're mapping relationships—government, political, activists, press.”

  A passive surveillance system. One that leaves no trace.

  “And they want you to finish it,” Azamat said, subdued.

  Vitya stared at his notebook. The stranger hadn't chosen him by chance. Knew his SIGINT experience, knew his mother, his skills.

  Katya leaned in, steady voice. “We don't stop here. We dismantle it. Look for fingerprints.”

  Vitya nodded. No programmer could vanish entirely; their code would yield traces—compiler patterns, coding style, hardware assumptions.

  He glanced at his watch—1:03. Stepping out of the shielded room, the relief carer's message glowed on his Nokia: “Oxygen 92%, stable. Left at 00:45.” Three hours till her next medication. Forty-two minutes home at this hour, with the night bus and the walk.

  Shifting, Vitya catalogued tasks: Disassemble the disc's binary payload, identify tells, correlate environmental cues—before 2:55.

  The café's silence magnified every sound: Katya's typing, Azamat's breathing, the hum of cooling fans. Irina reloading continuous paper into the Robotron printer's tractor feed.

  A mechanical shriek. The line printer lurched and started consuming the paper. Hex values spilt to the floor, page after page, piling in an uneven stack.

  Irina turned, amber light from the CRT illuminating her satisfied expression.

  “And we're off.”

  Vitya felt the fine texture of the dot matrix impacts along the accordion paper. A river of hex alongside the disassembled mnemonics and operands. Katya marked the disassembly, highlighter trailing fluorescent lines. Patterns emerged, but not the ones he expected.

  “Too clean,” he muttered, comparing hex dump with the code. “I'm not seeing any assembler signatures or unused strings. No compiler artefacts at all. Wiped of all fingerprints—register use, stack frames, memory spacing—it's sterile.”

  Katya nodded, her eyes never leaving the paper. “Yeah. Two-pass binary stripping. Probably built on a UNIX box then pushed straight to a Pentagon over SCSI.”

  The printer chattered on. Each page a study in anonymity.

  Azamat paced, nervous energy curdling. Stopping by the swelling mound of printouts, he said, “Someone who puts this much effort into recruitment is deathly serious. Rules out corporate security. No one paid in roubles cares this much.”

  Flexing his shoulders, Vitya's neck cracked. How long had he been hunched? Checking the time, he saw an hour remained before he had to leave.

  “I don't think we're going to get answers from the code,” he said, frustration edging in. “It's like looking at a sea of grey.”

  The café door rattled open. Dima's stocky frame appeared, accompanied by the scent of flux and cigarettes. Factory floor stains, oil, solder—he moved like a technician ready to intervene.

  “Factory meeting. Could not be helped.” He frowned, backpack thumping onto an empty chair. Eyes flicked to the printer and its ongoing spill of octets. “What did I miss?”

  Irina stepped away from her terminal. “We know the ‘how,’ now the ‘who.’ Someone's mapping networks by packet response, not content. And they're recruiting.”

  Dima's expression shifted from apology to focused intensity. “May I?” he asked, pointing at the Pentagon.

  Vitya made space. Kneeling, Dima examined the disk with a technician's care, fingers testing its edge as if it were a knife.

  “Western media. Recent. Not from a dead stock warehouse.”

  From his pack, he dug a Mitsumi floppy drive with visible modifications—its standard interface supplemented by wiring from a small circuit board mounted to its side. A mechanism Vitya recognized from SIGINT, built to detect faint magnetic flux transitions, employed in the recovery of partially erased data from diplomatic communications

  “You adjusted pulse detection threshold,” Vitya observed, noting the trimmer pots on the modification.

  Dima offered a faint smile. “They detect transitions in the sector gaps. Where normal drives see nothing.”

  The modified drive activated with a discordant whine, nothing like the familiar rhythm of a 3? inch drive. Dima tracked the lights, methodically sweeping the unused disk sectors.

  He adjusted another potentiometer on his circuit board attachment. “Last year, someone tried to hijack our PLCs with a floppy drop.” He talked to keep calm. His fingers moved precisely, tuning one of the potentiometers. “Idiot supervisor loaded a disc he picked up in the car park. Was only through blind luck he didn't have to hand over the safe contents in a paper bag.”

  Observing the LED indicators on Dima's custom board, Vitya noted the pattern sweep regularly before coalescing into a cluster in time with the intensifying grind of the drive's servo.

  “Police were no help, of course,” Dima continued, eyes fixed on the drive's activity lights.

  The café's amber light caught the subtle twist of his mouth.

  “We nabbed the ублюдок ourselves by tracing the disc to a replication shop in Biryulyovo.” Adjusting another component on his board, Dima added, “Left him hanging upside down from a lamp-post with his infected floppy on display.”

  Irina's laugh cut through the electronic hum—sharp, unexpected. Vitya glanced at her, noting how different she looked when genuine amusement broke through her professional facade.

  Katya divided her attention between the screen and the modified drive. “Is this safe? How many discs has this been tried with?”

  Eighteen minutes before he had to leave; enough for the data to arrive, not for disaster recovery.

  Dima shrugged, ambiguity in his, “A few.”

  Leaning forward, Katya scanned the passing hex values on screen. “Could that be something?” She gestured to an island of structure in the noise. “Looks like data from a previous replication… never properly cleared.”

  Vitya measured the statistical variance—an anomaly, subtle but real.

  “A look-up table?” he pondered, gesturing to the screen with his pencil. “Reference codes and decimals.”

  “Possibly. Something distributed to multiple sites,” Katya mused. “A klepto's holdings? Or some dying kombinat?”

  Irina reeled off industrial players: “Arsenal? SevMash? Kvant? Maybe Volgotekhnika?”

  Dima snorted. “Volgotekhnika would sell thread gauges to NATO if the cheque cleared. But recruiting off book?” A short laugh. “Feels unlikely.”

  Weighing the possibilities, Vitya considered Arsenal—his mother's employers—the ones who ruined her life.

  “Why expose themselves like this?” Irina asked.

  Vitya remembered the stranger's words at the party. The mention of his mother, calculated and personal. “Maybe they expect sympathy.”

  Dima laughed, the sound booming despite the dampening. “С лёгкого разума. Pushing their luck.”

  “Perhaps a warning?” Azamat said.

  “Join us or…” Irina let the rest trail.

  He glanced at his watch and felt the cold thud of realization. 3:07. He'd missed his Casio alarm. His mother needed her medication and oxygen adjustment.

  “I must go.” Standing, his calculations shifted from packets to bus routes. The night bus ran with long intervals. He'd walk part of it to save time.

  He gathered his notes, precise even in anxiety. Missing her schedule would destabilize her for days.

  “The disk,” Irina said. “We should destroy it.”

  Vitya shook his head. “If it's Arsenal—or Kvant—destroying evidence won't help. Keep analysing. Document everything. I'll return tomorrow.”

  Already back at the machine, Katya nodded. “We'll keep mapping the simulation. Look for more identifying markers.”

  Dima detached his modified drive. “I'll check for manufacturing signatures. Might reveal its origin.”

  Azamat looked up, unusually grave. “And now we know they exist.”

  Katya placed her hand on his shoulder, the unexpected contact making him tense.

  “We'll find out who they are,” she said, her voice low but determined. “I can cross reference—part numbers, tolerances.”

  Looking up, Vitya momentarily forgot his mother's medication schedule. “You have that kind of access?”

  A wry smile crossed Katya's face, transforming her features with a flash of confidence he rarely witnessed.

  “My father's network is… porous. Especially the procurement archives. He relies on outdated authentication passed down from his predecessor. A few well-placed queries…”

  Across the room, Irina twisted the heavy deadbolt, metal scraping against metal as she prepared to release him back into the Moscow night.

  “Vitya,” she said, her Dublin accent surfacing briefly, “whatever happens, you're not alone.”

  The words settled around him like unexpected parameters in a routine. Not alone. The concept felt foreign after years of solitary coding, of caring for his mother with only occasional relief from paid nurses.

  He nodded once, unable to formulate a proper response. The weight of his mother's needs pulled at him, her medication schedule ticking down in his mental counter.

  This was progress, having allies with skills that complemented his own. But if this disk was a warning, it was also a portent. His fingers tightened around his backpack strap. He could not be part of this fight.

  Pausing at the door, hand on the frame, Vitya saw the café's amber light throw their silhouettes long, his colleagues like geometric shapes from his demos—connected by invisible vectors.

  The night air rushed in as Irina opened the door, cold and clarifying. Moscow stretched before him, its streets mapped in his mind like memory addresses—the fastest route home already calculated.