NC Bench
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About
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Vendors
Run: 2026-02-17-01KHMQWPQP78PXQVKZHW4V8TAQ
Run Details
Model:
Claude Opus 4.6
Test:
Bad Writing Habits
Scenario:
Mystery: examining a crime scene
Duration:
1m 21s
Cost:
$0.078465
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 bone token felt like a dead man's tooth against Quinn's palm. She'd pulled it off a suspect two weeks back—a tweaker in Hackney who swore he'd found it in a skip—and had kept it in her coat pocket since, turning it over during long stakeouts the way some people worried rosary beads. She hadn't expected it to actually work. But here she was, thirty feet below Camden High Street, standing on a platform that hadn't seen a scheduled train since 1924,
look
ing at a dead body sprawled across what
appeared to
be a supernatural flea market. "Nobody touch anything else," Quinn said, though the only person close enough to hear her was Eva Kowalski, who
look
ed like she might faint. The abandoned station was larger than it should have been. Quinn had studied enough disused Tube maps to know the original platform dimensions, and this space exceeded them by a factor of three at least, the vaulted ceiling receding into a darkness that the emergency services' halogen lamps couldn't fully penetrate. Stalls lined both sides of the platform—wooden trestle tables, glass-fronted cabinets, a few that
look
ed like they'd
been knocked
together from salvaged coffin wood. Most had
been abandoned
in a hurry. Jars of unidentifiable liquids still sat in neat rows. A rack of what
appeared to
be animal pelts—though the shapes were wrong, the fur too iridescent—hung undisturbed on a brass rail. The vendors had fled, but they'd left their stock behind. They'd left everything behind except, apparently, any identification for the dead man at Quinn's feet. She crouched, knees popping, and pulled on a pair of nitrile gloves. The victim was male, late thirties, wearing a charcoal overcoat that had cost more than Quinn's monthly rent. No wallet. No phone. No rings, no
watch
, no labels in the coat—she checked. Someone had taken a blade to every tag with surgical care. His face was intact, but it wouldn't help; it had the slack, generalized quality of someone who hadn't quite settled on a final expression. His eyes were open. They were entirely black, both sclera and iris, as if someone had filled the sockets with ink. "That's not decomposition," Quinn said, more to herself than to Kowalski. "No. It's not." Eva's voice came from three feet to Quinn's left, closer than expected. The younger woman had her leather satchel clutched against her chest like a shield, her curly red hair electric in the halogen glare. She'd tucked it behind her left ear twice already in the last ninety seconds. Quinn counted. "It's exposure. To something. A rift, probably, or—he could have
look
ed directly into a Shade-class artifact without protection. The vitreous humor changes. It's documented in Marchetti's 1883 field notes, the ones the British Museum keeps in restricted—" She stopped herself, pushing her round glasses up with one knuckle. "Sorry. You asked me here to consult, not lecture." "I asked you here because you're the only person I know who doesn't think I'm mad." Quinn angled her torch along the dead man's hands. Clean fingernails. No defensive wounds. No bruising on the knuckles. Whoever he was, he hadn't fought back. Or hadn't had time to. "And because you can read whatever language that is." She pointed the beam toward the stall nearest the body. The table's surface
was covered
in a dark cloth embroidered with symbols Quinn couldn't place—not Arabic, not Hebrew, not any of the scripts she'd learned to recognize in eighteen years working London's more culturally diverse crime scenes. Sitting in the center of the cloth, in a
velvet
-lined box left carelessly open, was a small brass compass. Its casing was rough with verdigris, the face
etched
with marks that matched the ones on the cloth. The needle
trembled
. Eva leaned in, then immediately pulled back, reaching into her satchel for a pair of cotton archive gloves. "Don't touch that." "Wasn't going to." "I mean it, Quinn. That's a Veil Compass. Shade-crafted. It points toward the nearest supernatural rift." Eva's green eyes were wide behind her lenses, and for a moment Quinn saw something there that went beyond academic excitement—something closer to fear. "They sell them here. In the Veil Market. That's what this place is. Or was, before—" She gestured at the body. Quinn stood and took two steps back. She planted her feet shoulder-width apart, hands at her sides, and made herself
look
at the whole scene instead of the pieces. This was the discipline that eighteen years and a dead partner had drilled into her. The pieces would seduce you. The pieces would tell you a story you wanted to hear. You had to see the shape of the absence first—the thing that was missing. She turned
slowly
, her worn leather
watch
catching the light as she raised her wrist to check the time. Quarter past two in the morning. They'd been down here forty minutes. The stalls str
etched
away into the gloom in both directions, and the more Quinn
look
ed, the more she noticed details that troubled her. The jars on the nearest table
were arranged
by size, largest to smallest, with obsessive precision. The pelts hung at equal intervals. Even the knocked-together coffin-wood stalls had
been assembled
with care, their joints tight, their surfaces sanded smooth. "This is organized," Quinn said. "This whole market. It's not some anarchist pop-up. Someone runs it." "It moves every full moon," Eva said quietly. "Different abandoned station each time. The bone token gets you in. Beyond that, I don't know much—the archives reference it obliquely, mostly in confiscated journals. The vendors are a mix. Humans, mostly. Some of them... aren't." Quinn filed that away. She'd come back to it. Right now, the body
was talking
to her, and she needed to listen. She returned to the dead man and crouched again, this time examining the floor around him. The platform
was tiled
in the old London Underground style—cream and dark green, chipped and filthy with a century of disuse. Except around the body, where the tiles were clean. Not just clean—polished. A perfect circle, roughly six feet in diameter, with the dead man at its center. Quinn pulled a pen from her jacket and laid it on the tiles at the circle's edge. It rolled inward, toward the body, as if the floor were subtly concave. "Eva. Come
look
at this." Kowalski approached, satchel still pressed to her chest. She saw the pen rolling and her freckled face went pale. "Oh," she breathed. "Oh, that's not good." "Tell me what you're thinking." "I'm thinking this wasn't a murder. I'm thinking this was a transaction that went wrong." Eva pointed at the circle of clean tiles. "That's a summoning boundary. Or what's left of one—it's been partially scrubbed. Whoever set it up tried to clean up afterward but couldn't do a thorough job. The compass was part of the ritual setup. You use a Veil Compass to locate the thinnest point between here and—well, somewhere else. Then you open it. If you know what you're doing. If you don't..." She
look
ed at the dead man's black eyes. "The rift
look
s back." Quinn stared at her. "You're telling me he did this to himself." "I'm telling you that's one interpretation." "And yours?" Eva hesitated. She tucked a curl behind her left ear again and
look
ed at the stalls surrounding them—the neat rows of jars, the careful arrangements, the evidence of a market that functioned with the quiet efficiency of a well-run operation. "Mine
is that someone
set him up. Look at where he is. He's in the middle of the walkway, Quinn. Not behind a stall, not in a back room. He's right out in the open. If you were going to open a rift—which is, to be clear, extremely illegal even by Veil Market standards—you wouldn't do it in the main thoroughfare. You'd find a corner. A closet. Somewhere you wouldn't be interrupted." Quinn felt the familiar cold tightening at the base of her skull—the feeling she got when a case
began to
cohere. She'd felt it three years ago, standing in a rain-soaked car park in Southwark,
look
ing at the spot where DS Morris had been and then wasn't. The coroner had called it an unexplained disappearance. Quinn had called it a lie. She still called it that. She
look
ed at the circle again. At the dead man's clean hands, his expensive coat with its labels removed, his black and staring eyes. She
look
ed at the Veil Compass in its
velvet
box, needle still trembling, still pointing at something. "The compass," she said. "If it points toward the nearest rift, and there's no rift here now—where is it pointing?" Eva followed her gaze, then
carefully
leaned over the box without touching it. The color drained from her face entirely. "It's not pointing at a rift. It's pointing at him." She straightened up and backed away, nearly stumbling over a crate of what
appeared to
be bottled lightning. "Quinn, it's pointing at the body. He is the rift. Or—something came through, and it's still inside him, or—" "Stop." Quinn raised a hand. She needed to think. She needed the pieces to stop moving for one moment so she could see the shape. A man with no identification, expensive clothes stripped of all markers, positioned in the center of a public space in a hidden supernatural market. A summoning circle partially scrubbed away by someone with enough presence of mind to attempt concealment but not enough time to finish the job. A Shade-crafted compass left behind, pointing at the corpse. And the vendors—all of them—gone. "They didn't run because he died," Quinn said
slowly
. "They ran because of what's inside him. They knew. Whoever runs this market saw what happened and evacuated everyone before we got here." "Before anyone got here. Quinn, the Market doesn't let outsiders in. Even with a token, you shouldn't have been able to—" "Unless someone wanted me here." Quinn stood and
look
ed at the bone token in her left hand. She'd been turning it over without realizing, the nervous fidget of a detective who hadn't slept properly in three years. She held it up to the halogen light. There were marks on it she hadn't noticed before—fine scratches, almost imperceptible, forming shapes that
look
ed uncomfortably similar to the sigils on the Veil Compass. She thought of the tweaker in Hackney. Found it in a skip. Like hell he did. "Someone wanted a detective to find this body," Quinn said. "Someone who knows what I've been
look
ing into. Someone who knows about Morris." Eva stared at her. "You think this is connected to your partner's disappearance?" Quinn didn't answer immediately. She
look
ed at the dead man's black eyes, at the needle of the compass trembling in its brass case, at the clean circle of tiles on the floor of a station that hadn't been clean in a hundred years. She thought about Morris standing in the rain in Southwark, the way he'd turned to her and said something she couldn't hear, and then the dark had swallowed him like a mouth. The dead man's eyes were exactly the color of that dark. "Get your notes out," Quinn said. "Every reference to Shade artisans, summoning boundaries, and whatever Marchetti documented in 1883. I want it all." She pulled an evidence bag from her coat pocket and crouched beside the
velvet
box. With exquisite care, she closed the lid over the trembling compass and sealed it. "We're not calling this in to the Met. Not yet." "Quinn—" "Eighteen years, Kowalski. Eighteen years I've followed procedure, and procedure got Morris killed. Or taken. Or whatever happened to him." She met Eva's wide green eyes and held them. Her voice was steady. Her hands were steady. Everything was steady except the compass in the evidence bag, its needle still turning, still pointing at the dead man who might not be entirely dead. "This time," Detective Harlow Quinn said, "I'm following the evidence. Even if it leads somewhere impossible." She turned and walked deeper into the Veil Market, her torch cutting a path through the dark, and after a moment she heard Eva Kowalski's
footsteps
hurrying to catch up, the familiar sound of books shifting in a leather satchel, the quick breath of someone who
was terrified
but more afraid of being left behind. The bone token pulsed once in Quinn's pocket, warm against her thigh, and the darkness ahead of them
seemed to
lean closer, as if listening.
created_at
"2026-02-17T02:48:15.827327+00:00"
2/17/2026, 2:48:15 AM
model
"anthropic/claude-4.6-opus-20260205"
app_id
182717
external_user
(null)
streamed
true
cancelled
false
latency
1503
moderation_latency
(null)
generation_time
80854
tokens_prompt
923
tokens_completion
3159
native_tokens_prompt
938
native_tokens_completion
2951
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
0.078465
router
(null)
provider_responses
0
id
"msg_01AZCs7bQ3PeNXhXgvkBdxrd"
status
200
is_byok
false
latency
1503
endpoint_id
"c926c048-563e-44b0-8434-95965bee924c"
provider_name
"Anthropic"
model_permaslug
"anthropic/claude-4.6-opus-20260205"
api_type
"completions"
id
"gen-1771296414-YflPDrKU0GiETkN525AC"
upstream_id
"msg_01AZCs7bQ3PeNXhXgvkBdxrd"
total_cost
0.078465
cache_discount
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upstream_inference_cost
0
provider_name
"Anthropic"
Evaluation details
Result
Evaluator
Details
Meta Data
0.0000%
Adverbs in dialogue tags
Target: ≤10% dialogue tags with adverbs
totalTags
10
adverbTagCount
4
adverbTags
0
"Quinn said, though the only person close enough to hear her was Eva Kowalski, who looked like she might faint [only enough like]"
1
"Quinn said, more to herself than to Kowalski [more]"
2
"Eva said quietly [quietly]"
3
"Quinn said slowly [slowly]"
85.8290%
AI-ism adverb frequency
Target: <1% AI-ism adverbs (57 tracked)
wordCount
2117
totalAiIsmAdverbs
3
found
0
adverb
"carefully"
count
1
1
adverb
"slowly"
count
2
highlights
0
"carefully"
1
"slowly"
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)
71.6580%
AI-ism word frequency
Target: <1% AI-ism words (140 tracked)
wordCount
2117
totalAiIsms
6
found
0
word
"trembled"
count
1
1
word
"velvet"
count
3
2
word
"footsteps"
count
1
3
word
"etched"
count
1
highlights
0
"trembled"
1
"velvet"
2
"footsteps"
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
1
narrationSentences
118
matches
0
"was terrified"
100.0000%
Filter word density
Target: ≤12% sentences with filter/hedge words
filterCount
2
hedgeCount
5
narrationSentences
118
filterMatches
0
"look"
1
"watch"
hedgeMatches
0
"appeared to"
1
"began to"
2
"seemed to"
100.0000%
Overuse of "that" (subordinate clause padding)
Target: ≤10% sentences with "that" clauses
thatCount
1
totalSentences
141
matches
0
"is that someone"
100.0000%
Paragraph length variance
Target: CV ≥0.5 for paragraph word counts
totalParagraphs
49
mean
42.49
std
33.88
cv
0.797
sampleLengths
0
60
1
37
2
24
3
123
4
15
5
100
6
11
7
111
8
56
9
87
10
21
11
3
12
61
13
74
14
93
15
16
16
44
17
22
18
94
19
5
20
26
21
5
22
98
23
12
24
6
25
2
26
112
27
66
28
41
29
20
30
67
31
25
32
62
33
32
34
21
35
70
36
16
37
23
38
13
39
75
40
11
41
23
42
29
43
10
44
1
45
63
46
16
47
55
48
25
93.7853%
Passive voice overuse
Target: ≤5% passive sentences
passiveCount
7
totalSentences
118
matches
0
"been knocked"
1
"been abandoned"
2
"was covered"
3
"were arranged"
4
"been assembled"
5
"was tiled"
6
"was terrified"
100.0000%
Past progressive (was/were + -ing) overuse
Target: ≤10% past progressive verbs
pastProgressiveCount
1
totalVerbs
253
matches
0
"was talking"
98.8710%
Purple prose (modifier overload)
Target: <4% adverbs, <2% -ly adverbs, no adj stacking
wordCount
1550
adjectiveStacks
0
stackExamples
(empty)
adverbCount
64
adverbRatio
0.04129032258064516
lyAdverbCount
24
lyAdverbRatio
0.015483870967741935
100.0000%
Repeated phrase echo
Target: ≤20% sentences with echoes (window: 2)
totalSentences
141
echoCount
0
echoWords
(empty)
100.0000%
Sentence length variance
Target: CV ≥0.4 for sentence word counts
totalSentences
141
mean
14.77
std
12.53
cv
0.849
sampleLengths
0
12
1
41
2
7
3
37
4
24
5
10
6
41
7
24
8
7
9
9
10
22
11
10
12
15
13
12
14
18
15
2
16
2
17
10
18
11
19
24
20
4
21
17
22
11
23
15
24
23
25
14
26
2
27
48
28
9
29
25
30
2
31
3
32
5
33
7
34
5
35
9
36
10
37
37
38
19
39
18
40
3
41
18
42
3
43
3
44
40
45
21
46
7
47
22
48
15
49
5
49.1726%
Sentence opener variety
Target: ≥60% unique sentence openers
consecutiveRepeats
19
diversityRatio
0.375886524822695
totalSentences
141
uniqueOpeners
53
75.0000%
Dialogue tag variety (said vs. fancy)
Target: ≤30% fancy dialogue tags
totalTags
10
fancyCount
4
fancyTags
0
"Quinn said, though the only person close enough to hear her was Eva Kowalski, who looked like she might faint (say, hear look like faint)"
1
"Eva said quietly (say quietly)"
2
"she breathed (breathe)"
3
"Quinn said slowly (say slowly)"
86.7245%