NC Bench
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Run: 2026-02-17-01KHMQQ88QHQ9KC531QKA3BF7J
Run Details
Model:
Claude Opus 4.6
Test:
Bad Writing Habits
Scenario:
Thriller: chase through city streets
Duration:
1m 12s
Cost:
$0.068840
Provider:
Anthropic
Model input
System
You are an expert novelist with a gift for vivid, immersive prose. You write in tight third-person limited point of view with a strong narrative voice. Your prose is clean, precise, and engaging — you favor strong verbs, concrete details, and natural-sounding dialogue. You will be given a story bible (codex) containing canonical details about characters, locations, items, and lore. Use these details to ground your writing in the established world. Stay consistent with the codex. Write only the prose of the scene. Do not include titles, chapter headings, markdown formatting, or any commentary before or after the scene.
User/Human
<codex> <character id="4416" name="Detective Harlow Quinn" aliases="Quinn, Detective Quinn, Harlow" pronouns="she/her" species="Human" storyRole="Antagonist"> <eyeColor>brown</eyeColor> <hair>closely cropped salt-and-pepper</hair> <height>5'9"</height> <age>41</age> <jawline>sharp jaw</jawline> <watch>worn leather watch on her left wrist</watch> <bearing>military precision</bearing> <description>A Metropolitan Police detective with 18 years of decorated service who suspects the clique is involved in criminal activity.</description> <backstory>She lost her partner, DS Morris, during a case three years ago under unexplained circumstances that had supernatural origins she doesn't yet understand.</backstory> </character> <character id="4417" name="Tomás Herrera" aliases="Tommy, Tomás, Herrera" pronouns="he/him" species="Human" storyRole="Support"> <eyeColor>warm brown</eyeColor> <hair>short curly dark brown</hair> <height>5'10"</height> <age>29</age> <skinTone>olive skin</skinTone> <scar>scar running along his left forearm from a knife attack</scar> <medallion>Saint Christopher medallion around his neck</medallion> <birthplace>Seville, Spain</birthplace> <description>A former paramedic who provides off-the-books medical care for the clique.</description> <backstory>Born in Seville, Spain. He moved to London to work for the NHS but lost his license after administering unauthorized treatments to supernatural patients.</backstory> </character> <location id="854" name="The Raven's Nest" aliases="the Nest, Raven, Silas' bar" realm="Earth"> <signColor>distinctive green neon sign above the entrance</signColor> <secretRoom>hidden back room accessible through a bookshelf, used for clandestine meetings</secretRoom> <description>A dimly lit bar in Soho, London. The walls are covered with old maps and black-and-white photographs.</description> </location> <location id="856" name="The Veil Market" aliases="Veil Market, the Market, underground market" realm="Earth"> <currentLocation>abandoned Tube station beneath Camden</currentLocation> <entryRequirement>bone token</entryRequirement> <schedule>moves locations every full moon</schedule> <description>A hidden supernatural black market that sells enchanted goods, banned alchemical substances, and information.</description> </location> </codex> Write a fully fleshed out scene of at least 1000 words in the thriller genre. A detective is pursuing a suspect through rain-soaked city streets at night. The chase takes them from the street level down into an underground market. The detective must decide whether to follow the suspect into unfamiliar and potentially dangerous territory. Use the codex entries above as your world reference for characters and setting. Only include the prose of the scene without any markdown or commentary.
Model response
Messages
Meta
AI
The rain came sideways off the rooftops of Soho, sheeting across the narrow street in gusts that turned the neon signs into smeared watercolors against the dark. Harlow Quinn ran. Her boots hammered the slick pavement, each strike sending up a fan of dirty water, and she kept her eyes fixed on the figure thirty meters ahead—Tomás Herrera, moving fast for a man who claimed to be nothing more than a retired paramedic. He cut left past a kebab shop, its fluorescent glow painting him in a brief flash of white light, and she caught enough of his profile to confirm what she already knew: the dark curls, the olive skin, the way he moved with his left arm tucked
slightly
against his body, protective of that scar she'd seen in his NHS personnel file. He'd spotted her outside The Raven's Nest twenty minutes ago, standing in the doorway of the closed bookshop across the street, and the recognition had been instant and mutual. She'd
watch
ed his face change through the rain-streaked window of the bar—
watch
ed the easy warmth drain out of his expression like someone had pulled a plug—and then he was moving, slipping out a side exit she hadn't known existed. Now she was three streets from where she'd started and losing ground. Quinn pressed harder, her lungs burning with the cold November air. Eighteen years on the force had kept her fit, but she was forty-one and running in a wool coat that was rapidly becoming a sodden
weight
across her shoulders. She shrugged it off mid-stride, letting it fall to the pavement behind her, and felt immediately lighter. The worn leather
watch
on her left wrist caught the rain and clung to her skin. Herrera ducked right, disappearing around a corner onto a street she didn't recognize. She followed, her hand moving instinctively to the radio clipped at her hip, and then she stopped herself. She hadn't called this in. She wasn't supposed to be here. The surveillance on The Raven's Nest was her own operation, unofficial, built on three months of late nights and gut instinct and the kind of obsessive pattern recognition that her DCI had
gently
suggested she redirect toward cases that actually existed in the system. But the cases did exist. They just didn't make sense to anyone else. She rounded the corner and nearly lost her footing on a patch of wet leaves. The street opened onto a wider road—Camden High Street, she realized, which meant Herrera had covered more distance than she'd thought, or she'd gotten turned around in the rain. Neither possibility pleased her. She scanned the street, rain needling her face, and caught movement fifty meters ahead: Herrera, descending a set of stairs she'd never noticed before, half-hidden behind a construction hoarding that looked like it had been there for years. Quinn crossed the street at a dead sprint, weaving between a black cab and a night bus that blared its horn at her back. She reached the hoarding and found the stairs—concrete, uneven, leading down into what looked like the entrance to an old Tube station. The tiled archway above was cracked and dark, the station name long since stripped away, leaving only the ghost of adhesive residue in the shape of letters she couldn't read. She descended. The rain fell away above her, replaced by the hollow drip of water finding its way through aging infrastructure. The air changed—warmer, thicker, carrying a smell she couldn't immediately place. Something organic and sharp, like dried herbs burned over charcoal, layered beneath the mineral tang of old concrete and rust. At the bottom of the stairs, a short corridor opened into what had once been a ticket hall. A single bare bulb hung from a wire overhead, swinging faintly, casting restless shadows across the walls. And there, at the far end of the hall, stood a turnstile that looked original to the station—old brass, green with patina—manned by a figure Quinn couldn't quite focus on. Not because of the light, but because something about the figure
seemed to
refuse the eye, the way a word on the tip of your tongue refuses to form. Herrera was nowhere in sight. He'd gone through. Quinn approached the turnstile with measured steps, her hand resting on the grip of her extendable baton—her firearm
was locked
in the glovebox of her car six streets away, because she hadn't planned on a chase tonight, had only planned on
watch
ing and logging and adding another thread to the web of connections she'd been building on the corkboard in her flat. The figure behind the turnstile resolved
slightly
as she got closer: tall, impossibly thin, wearing what
appeared to
be a conductor's uniform from a bygone era. Its eyes were the wrong color. Not wrong like unusual—wrong like the color hadn't decided what it was yet. "Token," the figure said. Its voice was like a coin dropped down a well. "Metropolitan Police." Quinn held up her warrant card, keeping her expression flat, projecting the military precision that had gotten her through eighteen years and seven commendations and one night she still couldn't explain, the night DS Morris had walked into a warehouse in Bermondsey and never walked out, the night she'd found his radio on the floor still transmitting the sound of something that wasn't language. The figure looked at the warrant card with the polite disinterest of a customs official examining a library card. "Token," it repeated. "I'm in pursuit of a suspect. I saw him come through here. Stand aside." Nothing. The figure didn't move, didn't blink—if it had eyelids, Quinn couldn't confirm it in the fitful light. Behind the turnstile, she could see the corridor continuing, sloping downward toward what would have been the platforms. But the light down there was wrong, too. It
flickered
and moved the way firelight does, orange and amber, and she could hear sounds drifting up: voices, the clink of glass, the low thrum of activity that spoke of a crowd. A bone token. The phrase surfaced from somewhere in her research—an informant's whisper, a fragment she'd written on a sticky note and pressed to the corner of her bathroom mirror three weeks ago. The Veil Market. Moves every full moon. Entry requires a bone token. She looked up. Through the cracked ceiling of the ticket hall, she could see a sliver of night sky, and the moon—full, fat,
luminous
behind racing clouds. Quinn turned the warrant card over in her hand, thinking. Rain dripped steadily from the hem of her trousers, pooling at her feet. Everything in her training said to stop here. Unfamiliar environment. No backup. No firearm. No radio contact. A location that, by all official records, didn't exist. She
was standing
at the mouth of something she didn't understand, and the last time she'd done that—the last time she'd followed a thread into the dark—Morris had died and she'd spent three months on administrative leave and the department had buried the file so deep it might as well have
been cremated
. But Herrera was down there. And Herrera
was connected
to whatever
was operating
out of The Raven's Nest—that dimly lit bar with its old maps and black-and-white photographs and its bookshelf that she suspected opened onto something more than storage. She'd
watch
ed people go into that bar and not come out, or come out different, or come out with things in their pockets that hummed with a frequency she felt in her back teeth. She'd
been laughed
out of her DCI's office for suggesting it, and she'd learned to stop suggesting and start proving. Herrera was proof. If she could bring him in, sit him down under the flat lights of an interview room, she could crack the whole thing open. His NHS records alone
were damning
—dismissed for administering unauthorized treatments, but the file had
been redacted
in places that didn't correspond to standard privacy protocols. Somebody had reached into that file and pulled things out, the way you'd remove organs from a body cavity, leaving empty space where context should be. The figure at the turnstile waited with the patience of geography. Quinn's hand tightened on her baton. She thought about Morris—not the official version, not the photo on the memorial wall at the station, but the real Morris, with his terrible puns and his meticulous case notes and the look on his face, preserved forever on the warehouse CCTV, in the half-second before the footage corrupted into static. The look of someone who'd just seen a door open onto something vast and incomprehensible and had walked through it anyway, because that was the job. She reached into her trouser pocket. Her fingers closed on something hard and smooth that hadn't been there before—or had it? She pulled it out and stared at it in the swinging light: a small disc of bone, yellowed with age, carved with a symbol she'd seen in the margins of a file that wasn't supposed to exist. She didn't know where it had come from. She didn't know how long she'd been carrying it. The realization should have frightened her, and it did, but beneath the fear was something sharper and more dangerous—the absolute, granite certainty that she
was meant
to be here. She placed the token on the brass plate of the turnstile. The figure's not-quite-eyes shifted. Something that might have been surprise crossed its improbable face. Then it stepped aside, and the turnstile clicked and gave way under her hand. Quinn stepped through. The corridor descended in a slow curve, the walls transitioning from cracked tile to raw stone to something older, something that predated the Tube network by centuries. The air grew warmer. The sounds grew clearer—a babble of voices in languages she recognized and some she didn't, the clatter of what might have been commerce, a distant strain of music played on instruments that produced notes she felt more than heard. The flickering amber light intensified until she rounded a final corner and stopped. The Veil Market opened below her like a wound in the earth. The abandoned platform had
been transformed
—or perhaps it had always been this and the station above was the disguise. Stalls crowded every surface, constructed from materials that ranged from ordinary timber to what
appeared to
be ribcages of animals too large to name. Lanterns hung from the vaulted ceiling on chains of no visible metal, burning with flames that were the wrong hue, too gold, too steady. Hundreds of figures moved between the stalls—some of them human, some of them almost human, and some of them things that Quinn's mind could only process in fragments, the way you can only look at the sun in peripheral vision. She scanned the crowd for Herrera. Her heart
was hammering
so hard she could feel her pulse in her throat, in the worn leather of her
watch
strap, in the soles of her feet. Every instinct she'd honed in eighteen years
was screaming
contradictory instructions: flee, fight, observe, document, survive. She chose to observe. She chose to go further in. Quinn straightened her spine, set her sharp jaw, and descended into the market, a detective stepping off the edge of the map into the place where the maps on The Raven's Nest's walls had been pointing all along. Behind her, the turnstile clicked shut. Below her, the Veil Market
churned
and breathed and waited, and somewhere in its depths, Tomás Herrera
was running
out of places to hide.
created_at
"2026-02-17T02:45:08.451017+00:00"
2/17/2026, 2:45:08 AM
model
"anthropic/claude-4.6-opus-20260205"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1786
moderation_latency
(null)
generation_time
72073
tokens_prompt
914
tokens_completion
2900
native_tokens_prompt
918
native_tokens_completion
2570
native_tokens_completion_images
(null)
native_tokens_reasoning
0
native_tokens_cached
0
num_media_prompt
(null)
num_input_audio_prompt
(null)
num_media_completion
0
num_search_results
(null)
origin
"https://ncbench.com/"
is_byok
false
finish_reason
"stop"
native_finish_reason
"stop"
usage
0.06884
router
(null)
provider_responses
0
id
"msg_017CejpmUJobc8Viv7qGEjs1"
status
200
is_byok
false
latency
1786
endpoint_id
"c926c048-563e-44b0-8434-95965bee924c"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.6-opus-20260205"
api_type
"completions"
id
"gen-1771296235-7D5z3ZuJTUD70RNoPTp2"
upstream_id
"msg_017CejpmUJobc8Viv7qGEjs1"
total_cost
0.06884
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
100.0000%
Adverbs in dialogue tags
Target: ≤10% dialogue tags with adverbs
totalTags
2
adverbTagCount
0
adverbTags
(empty)
84.6233%
AI-ism adverb frequency
Target: <1% AI-ism adverbs (57 tracked)
wordCount
1951
totalAiIsmAdverbs
3
found
0
adverb
"gently"
count
1
1
adverb
"slightly"
count
2
highlights
0
"gently"
1
"slightly"
100.0000%
AI-ism character names
Target: 0 AI-default names (17 tracked, −20% each)
codexExemptions
(empty)
found
(empty)
100.0000%
AI-ism location names
Target: 0 AI-default location names (33 tracked, −20% each)
codexExemptions
(empty)
found
(empty)
79.4977%
AI-ism word frequency
Target: <1% AI-ism words (140 tracked)
wordCount
1951
totalAiIsms
4
found
0
word
"luminous"
count
1
1
word
"churned"
count
1
2
word
"flickered"
count
1
3
word
"weight"
count
1
highlights
0
"luminous"
1
"churned"
2
"flickered"
3
"weight"
100.0000%
Cliche density
Target: ≤1 cliche(s) per 800-word window
totalCliches
0
maxInWindow
0
found
(empty)
highlights
(empty)
100.0000%
Emotion telling (show vs. tell)
Target: ≤3% sentences with emotion telling
emotionTells
0
narrationSentences
105
matches
(empty)
100.0000%
Filter word density
Target: ≤12% sentences with filter/hedge words
filterCount
2
hedgeCount
3
narrationSentences
105
filterMatches
0
"watch"
hedgeMatches
0
"seemed to"
1
"appeared to"
100.0000%
Overuse of "that" (subordinate clause padding)
Target: ≤10% sentences with "that" clauses
thatCount
0
totalSentences
106
matches
(empty)
100.0000%
Paragraph length variance
Target: CV ≥0.5 for paragraph word counts
totalParagraphs
35
mean
54.83
std
37.76
cv
0.689
sampleLengths
0
73
1
130
2
12
3
73
4
86
5
13
6
86
7
76
8
52
9
94
10
8
11
107
12
14
13
66
14
22
15
14
16
77
17
45
18
27
19
102
20
94
21
78
22
11
23
83
24
104
25
11
26
28
27
3
28
83
29
12
30
107
31
50
32
4
33
6
34
68
88.8889%
Passive voice overuse
Target: ≤5% passive sentences
passiveCount
7
totalSentences
105
matches
0
"was locked"
1
"been cremated"
2
"was connected"
3
"been laughed"
4
"been redacted"
5
"was meant"
6
"been transformed"
100.0000%
Past progressive (was/were + -ing) overuse
Target: ≤10% past progressive verbs
pastProgressiveCount
6
totalVerbs
317
matches
0
"was standing"
1
"was operating"
2
"were damning"
3
"was hammering"
4
"was screaming"
5
"was running"
100.0000%
Purple prose (modifier overload)
Target: <4% adverbs, <2% -ly adverbs, no adj stacking
wordCount
1933
adjectiveStacks
0
stackExamples
(empty)
adverbCount
60
adverbRatio
0.031039834454216243
lyAdverbCount
17
lyAdverbRatio
0.008794619762027936
100.0000%
Repeated phrase echo
Target: ≤20% sentences with echoes (window: 2)
totalSentences
106
echoCount
0
echoWords
(empty)
100.0000%
Sentence length variance
Target: CV ≥0.4 for sentence word counts
totalSentences
106
mean
18.1
std
14.54
cv
0.803
sampleLengths
0
27
1
3
2
43
3
62
4
29
5
39
6
12
7
11
8
29
9
17
10
16
11
13
12
18
13
5
14
6
15
44
16
5
17
8
18
15
19
29
20
4
21
38
22
24
23
22
24
30
25
2
26
19
27
11
28
20
29
18
30
17
31
30
32
29
33
5
34
3
35
62
36
26
37
6
38
13
39
4
40
10
41
66
42
19
43
3
44
14
45
1
46
17
47
18
48
8
49
33
47.7987%
Sentence opener variety
Target: ≥60% unique sentence openers
consecutiveRepeats
16
diversityRatio
0.37735849056603776
totalSentences
106
uniqueOpeners
40
50.0000%
Dialogue tag variety (said vs. fancy)
Target: ≤30% fancy dialogue tags
totalTags
2
fancyCount
1
fancyTags
0
"it repeated (repeat)"
91.2240%