NC Bench
Overview
About
Tests
Models
Vendors
Run: 2026-02-17-01KHMQVF2XDFXNDTZZH7D8RTN5
Run Details
Model:
Claude Opus 4.6
Test:
Bad Writing Habits
Scenario:
Mystery: examining a crime scene
Duration:
1m 19s
Cost:
$0.075690
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="4414" name="Eva Kowalski" aliases="Eva, Evie" pronouns="she/her" species="Human" storyRole="Best Friend"> <eyeColor>green</eyeColor> <hair>curly red</hair> <height>5'4"</height> <age>26</age> <glasses>round glasses</glasses> <satchel>worn leather satchel full of books</satchel> <freckles>freckled complexion</freckles> <nervousHabit>tucking hair behind her left ear</nervousHabit> <description>Aurora's childhood friend and an occult researcher.</description> <backstory>Moved to London two years before Aurora and works as a research assistant at the British Museum's restricted archives. She holds a master's degree in Ancient History from Oxford.</backstory> </character> <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> <item id="2004" name="Veil Compass" aliases="the Compass, shadow compass" type="Tool" origin="The Veil Market"> <casingMaterial>small brass compass</casingMaterial> <faceMarkings>face etched with protective sigils</faceMarkings> <needle>points toward the nearest supernatural rift or portal</needle> <patina>casing has a patina of verdigris</patina> <creator>crafted by a Shade artisan</creator> <description>A compass attuned to supernatural energy.</description> </item> </codex> Write a fully fleshed out scene of at least 1000 words in the mystery genre. A detective arrives at a crime scene in an unusual location. Something is wrong — the evidence doesn't add up. A colleague is present, offering a different interpretation. Through careful observation and deduction, the detective begins to see what others have missed. 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 escalator had been dead for decades, its corrugated steps frozen mid-descent like the vertebrae of some fossilized beast. Quinn planted her feet on the metal treads and walked down the old-fashioned way, her torch cutting a narrow cone through air that tasted of rust and standing water. The beam caught graffiti on the curved walls—tags and symbols she didn't recognize, spiraling into the darkness below. "Watch the third step from the bottom," called the uniformed constable stationed at the top. "Collapsed inward." She stepped over it without looking back. The abandoned platform opened up around her like the ribcage of something gutted and left to rot. Victorian tile clung to the walls in patches, cream and oxblood, the station's original name still partially visible in faded
mosaic
: — DEN TOW —. Camden Town, or what had once been an auxiliary platform beneath it, sealed off during the war and never reopened. Quinn had pulled the TfL records herself on the drive over. According to Transport for London, this space didn't exist. No maintenance schedules, no safety inspections, no electrical hookups since 1941. And yet someone had been here. Someone had set up shop. The platform
was gutted
. That was the first wrong thing. When the 999 call had come in—anonymous, routed through a burner—the responding officers had found the entrance pried open from what had been a bricked-up service corridor behind a kebab shop on Kentish Town Road. They'd followed the corridor down, through a passage that shouldn't have connected to anything, and found this: an open platform space roughly forty meters long, strung with the remnants of market stalls. Wooden trestle tables overturned. Canvas awnings torn down and trampled. Glass jars shattered across the concrete, their contents leaking into the grout lines between tiles—liquids in colors Quinn had no name for. One was phosphorescent, a faint chemical green that pulsed like a heartbeat in her peripheral vision but went still whenever she looked directly at it. And in the center of it all, the body. Quinn crouched beside it, pulling on nitrile gloves with the practiced snap of someone who'd done this several thousand times. Male, mid-fifties, heavyset, wearing a waxed canvas apron over layers of mismatched clothing. His hands
were covered
in what looked like soot, ground deep into the whorls of his fingerprints. His expression
was frozen
in something between surprise and recognition, as though he'd turned to greet someone he knew and found something else entirely. No visible wounds. No blood. No signs of a struggle on the body itself, though the surrounding market stalls told a different story. She leaned closer. The man's eyes were open, pupils blown wide despite the beam of her torch. The sclera had gone dark—not bloodshot, not hemorrhaged, but stained, as if someone had dropped ink into milk. She'd never seen anything like it. "Pathologist's initial read is cardiac arrest," said DS Reeves, picking his way through the debris to stand behind her. He was young, eager, holding his tablet like a clipboard. "Possibly drug-related. There's paraphernalia everywhere. Some kind of underground market—drugs, counterfeit goods. Vice is going to want a piece of this." Quinn said nothing. She
was looking
at the dead man's left hand, which was closed around something. She tilted her head, studying the way the fingers curled. "Have we photographed the hands?" "Scene of crime's been through. Full sweep." She used a pen to
gently
lever the fingers open. Nestled in the dead man's palm was a small disc of bone, roughly the size of a fifty-pence piece, carved with a symbol she didn't recognize—a circle bisected by a wavy line, with smaller marks radiating outward like the points of a compass rose. "Bag this separately," she said. "And I want a close-up photograph before it goes to evidence." Reeves crouched beside her, frowning at the token. "Some kind of club membership? Entry pass?" "Could be." Quinn straightened and swept her torch across the platform again, slower this time. She
wasn't looking
at the obvious wreckage. She
was looking
at the gaps—the places where things should have been and weren't. The market stalls, for instance. Roughly twenty of them, arranged in two facing rows like a proper street market. Most had
been overturned
, their wares scattered. But three of them—the three nearest the tunnel mouth at the far end of the platform—had
been cleared
. Not knocked over. Cleared. The tables were still standing, their surfaces wiped clean. Whatever had been sold there was gone, removed with care while the rest of the market descended into chaos. "Reeves. Come here." She led him to the nearest of the three clean stalls. The trestle table was old pine, scarred with use, but the surface had
been wiped
down with something that left a faintly oily residue. Quinn held her gloved finger up to the light. The residue caught it with an iridescent sheen, like petrol on wet tarmac. "Someone cleaned up," she said. "While whatever happened here was happening, someone took the time to pack their inventory and wipe their surfaces." "So they knew it was coming." "Or they caused it." She turned to face the tunnel mouth. The darkness there was absolute, her torch beam swallowed after a few meters as though the air itself thickened. A draft came from that direction, steady and cold, carrying a smell she couldn't place—ozone and something older, like the air inside a church crypt. "Where
does that tunnel
lead?" "Nowhere, according to TfL. Dead end. Bricked up about thirty meters in." "Have we confirmed that?" Reeves hesitated. "Not yet. The responding officers said it felt—they described it as disorienting. One of them got about ten meters in and came back saying the walls didn't seem right. That the distance felt wrong." Quinn filed that away without comment. She'd learned, in eighteen years, to listen to what uniformed officers said when they thought nobody important was paying attention. They felt things that detectives
were trained
to rationalize away. She turned back to the body. Crouched again. This time she looked not at the man but at the ground around him. The concrete floor was filthy—decades of dust and grime—which made it a perfect recording surface. She could read the foot traffic like sediment layers. Dozens of prints overlapping, the chaos of a crowd in motion. But around the body, in a radius of roughly two meters, the dust was undisturbed. No footprints. No knee marks from someone checking on him. No drag marks. The man had died in a void. People had fled around him, past him, but not one person had come close enough to leave a mark. "He wasn't trampled," she said. "He wasn't pushed. Everyone avoided him. Look at the flow pattern—the crowd splits here, reconnects here." She traced the arc with her torch. "They were already running when he went down, but they gave him a wide berth. Two meters, at least. As if they knew." "Knew he was dying?" "Knew not to touch him." She stood and turned a slow circle, cataloguing. The shattered jars, the overturned tables, the torn awnings, the clean stalls, the bone token, the impossible tunnel, the dead man with ink-black eyes in his perfect circle of undisturbed dust. Cardiac arrest, Reeves had said. Drug-related. Vice would want a piece. None of it fit. The evidence was a sentence written in a language she almost recognized, each word nearly making sense on its own but the grammar alien, the syntax wrong. She'd felt this before—three years ago, standing over DS Morris in an alley in Whitechapel, looking at a body that bore no marks and a scene that told a story no one could read. That case was still open. That case would always be open, because Quinn had never been able to make the evidence say what it so clearly wanted to say. She pulled out her phone and took her own photographs, separate from the official scene-of-crime record. The bone token. The clean stalls. The circle of untouched dust. The dark eyes. "Detective Quinn?" She looked up. Reeves
was holding
something he'd found beneath one of the overturned tables—a small brass object, verdigris-green with age, roughly the size of a pocket
watch
. He held it out on his gloved palm. Quinn took it and turned it in the torchlight. A compass, or something that looked like one. The casing
was etched
with symbols that matched nothing in her experience—delicate, precise marks that reminded her, with a jolt, of the carvings on the bone token. The needle under the glass was dark, almost black, and it
wasn't pointing
north. It
was pointing
toward the tunnel mouth. As she
watch
ed, the needle
trembled
and swung five degrees to the left, then steadied. Then swung again. Tracking something. "Compass is broken," Reeves said. Quinn closed her fingers around it. The brass was warm—warmer than it should have been, sitting on cold concrete in an underground station. She could feel a faint vibration through the metal, the suggestion of a pulse, as though the thing were alive. "It's not broken," she said quietly. "It's working
perfectly
. We just don't know what it's pointing at." She slipped the compass into an evidence bag, sealed it, and wrote the date, time, and location on the label in her small, precise handwriting. Then she stood in the ruins of the market that shouldn't exist, in the station that wasn't on any map, beside a body that bore no wounds, and did what she always did when the world refused to make sense. She started over. From the beginning. From the evidence. "I want the full tox screen expedited," she told Reeves. "I want a geological survey of that tunnel. I want every CCTV camera within three hundred meters of the kebab shop entrance pulled and reviewed—seventy-two hours back, minimum. And I want to know who this man is. Someone knew him. Someone sold him that token." Reeves was already tapping notes into his tablet. "Vice is going to flag this as theirs." "Vice can flag whatever they like. This is a suspicious death in my jurisdiction with no identifiable cause, and until the pathologist tells me otherwise, I'm treating it as a potential homicide." She looked once more at the tunnel mouth, at the darkness that swallowed light, at the compass needle in its sealed bag that was even now swinging
gently
in her coat pocket. "There's something here, Reeves. Something we're not equipped to see yet." She climbed the dead escalator back toward the surface, toward the noise and light of Camden at midnight, and with every step she felt the pull of the tunnel at her back—a gravity, a summons, like the tug of a current beneath still water. Three years ago, Morris had died with that same black staining in his eyes. She hadn't told anyone that. She hadn't written it in the report, because she hadn't understood it, and Harlow Quinn did not commit to paper things she could not defend. But she'd seen it. She'd knelt beside her partner's body in that Whitechapel alley and
watch
ed the darkness bloom across the whites of his eyes like ink dropped into milk, and she'd known—known with a certainty that lived in her bones rather than her brain—that whatever had killed him was not in any forensic textbook. Now she'd seen it again. Quinn emerged into the cold Camden air, checked her worn leather
watch
—half past one—and made a decision. Tomorrow she would pull the Morris file from storage. She would lay the old photographs beside the new ones. She would find the thread that connected a dead man in a hidden market to a dead man in a Whitechapel alley, because there was a thread, and it would lead somewhere, and she would follow it with the same
methodical
, relentless patience that had closed every case she'd ever
been given
. Except one. She walked to her car, the bone token and the strange compass sealed in evidence bags in her coat, and she did not look back at the dark mouth of the passage behind the kebab shop, though she felt it
watch
ing her go with something that was not quite indifference.
created_at
"2026-02-17T02:47:33.372019+00:00"
2/17/2026, 2:47:33 AM
model
"anthropic/claude-4.6-opus-20260205"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1705
moderation_latency
221
generation_time
78464
tokens_prompt
923
tokens_completion
3116
native_tokens_prompt
938
native_tokens_completion
2840
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
0.07569
router
(null)
provider_responses
0
id
"msg_01LybruTbAxeCvdDJDHVH77u"
status
200
is_byok
false
latency
1703
endpoint_id
"c926c048-563e-44b0-8434-95965bee924c"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.6-opus-20260205"
api_type
"completions"
id
"gen-1771296373-8EBRJs27RbZPcwHYemlO"
upstream_id
"msg_01LybruTbAxeCvdDJDHVH77u"
total_cost
0.07569
cache_discount
(null)
upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
91.6667%
Adverbs in dialogue tags
Target: ≤10% dialogue tags with adverbs
totalTags
8
adverbTagCount
1
adverbTags
0
"she said quietly [quietly]"
85.5491%
AI-ism adverb frequency
Target: <1% AI-ism adverbs (57 tracked)
wordCount
2076
totalAiIsmAdverbs
3
found
0
adverb
"gently"
count
2
1
adverb
"perfectly"
count
1
highlights
0
"gently"
1
"perfectly"
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)
80.7322%
AI-ism word frequency
Target: <1% AI-ism words (140 tracked)
wordCount
2076
totalAiIsms
4
found
0
word
"mosaic"
count
1
1
word
"trembled"
count
1
2
word
"methodical"
count
1
3
word
"etched"
count
1
highlights
0
"mosaic"
1
"trembled"
2
"methodical"
3
"etched"
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
131
matches
(empty)
100.0000%
Filter word density
Target: ≤12% sentences with filter/hedge words
filterCount
2
hedgeCount
0
narrationSentences
131
filterMatches
0
"watch"
hedgeMatches
(empty)
100.0000%
Overuse of "that" (subordinate clause padding)
Target: ≤10% sentences with "that" clauses
thatCount
1
totalSentences
152
matches
0
"does that tunnel"
100.0000%
Paragraph length variance
Target: CV ≥0.5 for paragraph word counts
totalParagraphs
55
mean
37.07
std
30.4
cv
0.82
sampleLengths
0
66
1
17
2
7
3
104
4
10
5
124
6
9
7
74
8
23
9
41
10
50
11
27
12
5
13
7
14
54
15
16
16
15
17
36
18
76
19
3
20
57
21
23
22
6
23
60
24
12
25
4
26
36
27
36
28
85
29
26
30
51
31
4
32
5
33
50
34
94
35
30
36
2
37
36
38
65
39
20
40
5
41
43
42
17
43
65
44
9
45
55
46
16
47
75
48
44
49
14
82.4427%
Passive voice overuse
Target: ≤5% passive sentences
passiveCount
10
totalSentences
131
matches
0
"was gutted"
1
"were covered"
2
"was frozen"
3
"been overturned"
4
"been cleared"
5
"been sold was gone"
6
"been wiped"
7
"were trained"
8
"was etched"
9
"been given"
100.0000%
Past progressive (was/were + -ing) overuse
Target: ≤10% past progressive verbs
pastProgressiveCount
6
totalVerbs
291
matches
0
"was looking"
1
"wasn't looking"
2
"was looking"
3
"was holding"
4
"wasn't pointing"
5
"was pointing"
88.0000%
Purple prose (modifier overload)
Target: <4% adverbs, <2% -ly adverbs, no adj stacking
wordCount
1736
adjectiveStacks
2
stackExamples
0
"current beneath still water."
1
"same methodical, relentless patience"
adverbCount
47
adverbRatio
0.02707373271889401
lyAdverbCount
15
lyAdverbRatio
0.008640552995391706
100.0000%
Repeated phrase echo
Target: ≤20% sentences with echoes (window: 2)
totalSentences
152
echoCount
0
echoWords
(empty)
100.0000%
Sentence length variance
Target: CV ≥0.4 for sentence word counts
totalSentences
152
mean
13.41
std
11.65
cv
0.868
sampleLengths
0
19
1
29
2
18
3
15
4
2
5
7
6
17
7
25
8
20
9
11
10
9
11
11
12
6
13
5
14
4
15
6
16
35
17
32
18
4
19
6
20
22
21
25
22
9
23
20
24
13
25
17
26
24
27
3
28
2
29
18
30
3
31
14
32
18
33
6
34
19
35
10
36
21
37
3
38
14
39
10
40
5
41
7
42
10
43
44
44
5
45
11
46
8
47
7
48
15
49
7
56.3596%
Sentence opener variety
Target: ≥60% unique sentence openers
consecutiveRepeats
21
diversityRatio
0.42105263157894735
totalSentences
152
uniqueOpeners
64
81.2500%
Dialogue tag variety (said vs. fancy)
Target: ≤30% fancy dialogue tags
totalTags
8
fancyCount
3
fancyTags
0
"called the uniformed constable stationed at the top (call uniform station)"
1
"said DS Reeves, picking his way through the debris to stand behind her (say pick stand)"
2
"she said quietly (say quietly)"
92.1177%