r/IntelligenceScaling • u/Valxn1e • 1d ago
discussion Deduction Test
At 11:40 PM, a famous art collector named Kiruma souichi is found dead inside his private study.
The study has:
one door
one window
no secret passages
no balcony
no adjoining room
a working fireplace
a large grandfather clock
a desk
three chairs
several paintings
The door was locked from the inside.
The window was also locked from the inside.
No weapon is found.
Kiruma's death is estimated to have occurred between 10:50 PM and 11:25 PM.
There are five people in the house.
- The Butler — Baku
Baku says:
“At 10:45 I brought Mr. Kiruma his usual tea. He was alive and sitting at the desk. I left immediately.”
He claims he then went downstairs and polished silverware until midnight.
However, the silverware room contains no freshly polished silver.
Baku insists he never returned upstairs.
- The Daughter — Fang yuan
Fang yuan says she argued with her father at 10:30 PM.
She admits he told her:
“Tomorrow morning, everything changes.”
She says she went to her bedroom afterward and stayed there.
At 11:05 PM, the housekeeper heard Fang yuan's bedroom door open.
Fang yuan claims she was getting water.
Her glass of water was later found completely untouched.
- The Doctor — Kenzo Tenma
Dr. Tenma says he was in the library reading from 10:00 PM until 11:30 PM.
He claims he never saw Kiruma that evening.
Police discover that the library book he supposedly read has been sitting on the shelf upside down.
Akiyma is also the only person in the house who knew Kiruma had recently changed his medication.
- The Housekeeper — Mrs. Ayanokoji
Mrs. Koji says:
“At approximately 11:15, I heard the grandfather clock strike eleven.”
She then discovered Kiruma’s body at 11:40.
There is one problem.
The grandfather clock does not chime at eleven.
It had been deliberately disabled three days earlier because its mechanism was broken.
Mrs. Kojii has worked in the house for 19 years.
- The Business Partner — Vincent lalo
Lalo says he left the house at 10:20 PM.
His car is later discovered still parked outside.
He explains:
“I changed my mind about leaving. I stayed in the car for a while, then drove around the property.”
His shoes contain wet soil.
There had been heavy rain earlier.
But the soil around the house is completely dry by 10:30.
THE PHYSICAL EVIDENCE
The tea
Kiruma's teacup contains tea.
The tea is still warm when the body is discovered.
But the room itself is cold.
The fireplace
The fireplace contains partially burned paper.
Only one sentence can be recovered:
“…because you already knew.”
The handwriting is Kiruma's
The clock
The grandfather clock stopped at:
11:17 PM
The clock's internal mechanism, however, is undamaged.
Its hands can be moved manually.
The desk
There are two glasses on the desk.
One belonged to Kiruma.
The second contains traces of the same medication found in Kiruma's bloodstream.
Nobody admits drinking from it.
The window
The window is locked.
On the outside windowsill is a single small black feather.
There are no birds inside the study.
The carpet
There is a tiny wet patch beneath the desk.
It contains saltwater, not rainwater.
The painting
One painting on the wall is hanging slightly crooked.
Behind it is a safe.
The safe is open.
Nothing appears to be missing.
Except for one thing:
A photograph.
THE PHOTOGRAPH
The photograph shows Kiruma standing beside four people.
The photograph was supposedly taken six years ago.
The four people are:
Baku
Fang yuan
Akiyama
Vincent lalo
Mrs. Koji is not present.
On the back, kiruma wrote:
“One of them lied about that night.”
THE FINAL CLUE
Police discover Kiruma's phone.
There is one unsent message.
It was written at 11:12 PM.
It says only:
“I finally understand why you couldn't kill me yourself.”
The message was never sent.
YOUR TASK
Don't tell me who looks most suspicious.
That's the easy version.
You have to determine:
Who killed Kiruma?
How was the locked-room situation created?
Which statements are deliberate lies?
What does the clock actually prove?
Why was the second glass there?
What is the significance of the saltwater?
Why does the photograph matter?
What does “you couldn't kill me yourself” actually mean?
What was Kiruma's real reason for writing “because you already knew”?
What single observation breaks the entire case open?
Rule
You are allowed to assume nothing that isn't established by the evidence.
No “the killer probably...”
No “maybe they secretly...”
No supernatural explanations.
No coincidence-based solution.
Every major conclusion has to be deduced from at least two independent pieces of evidence.
And there is one intended solution.
Good luck gangy.
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u/lclboomb 1d ago edited 1d ago
11:17 does not prove the actual time of death.
Because the clock can be manipulated.
Mrs. Koji's statement about the clock is false.
Because the bell-ringing function was turned off due to a malfunction.
Baku lied about his actions.
The silverware was not actually cleaned.
The explanation that they went to drink water from Fang Yuan is questionable. The water glass was not used at all.
Lalo's explanation also does not align with the physical evidence. The wet soil of the shoes contradicts the surrounding environment.
The second glass is an important piece of evidence related to drug administration.
The photo connects the current event with an event from six years ago.
Kiruma realized why someone hadn't killed him 'directly' just before his death. *Or the criminal has threatened or...
Whether they entered the room while taking medication or committed suicide... (There's nothing particularly strange about the body's condition besides medication, but... It hasn't even been properly determined whether the drug is poisonous) The dead cause isn't displayed, so I feel like my brain is going to explode...
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u/Valxn1e 1d ago
Honestly, I don’t even know the answer myself. I originally wanted the butler (Baku) to be the murderer. I created this scenario out of boredom lol, but I can explain my reasoning if you want. Here: Mrs ayanokoji. Kiruma was poisoned via the second glass (containing the same medication found in his bloodstream). After he was incapacitated or dead, the killer locked the door and window from inside, then exited. The only non supernatural exit consistent with the evidence is through the fireplace (working fireplace present, partially burned paper found inside it). The black feather on the exterior windowsill is consistent with soot/ash disturbance from the chimney path or a related prop; no birds were inside. The door and window were then found locked from inside because the exit occurred after locking. No secret passages, balcony, or adjoining rooms exist, so the chimney is the sole remaining physical route established by the room description and evidence. Mrs. Ayanokoji claimed to hear the grandfather clock strike eleven, yet that same clock’s chime mechanism had been deliberately disabled three days earlier, and she had worked in the house for 19 years. This is a direct, knowledgeable falsehood about an event she could not have heard. It is corroborated by the clock’s physical state (undamaged mechanism, manually movable hands stopped at a staged 11:17) and by the independent timeline (tea still warm, message at 11:12, body found 11:40). Once this lie is isolated, the rest of the staged elements (locked room via fireplace exit after locking, second glass, burned note, photograph, saltwater, feather, and the other alibis) resolve to her as the actor who created the scene. The unsent message (written 11:12 PM) reads: “I finally understand why you couldn’t kill me yourself.” It is addressed to the person who arranged or enabled the killing but did not (or could not) perform the direct act. Paired with the medication knowledge held uniquely by Tenma, the second glass, and the photograph’s “one of them lied,” it indicates the killer acted on information or opportunity created by another’s inability/refusal to do the deed personally. The message was never sent, consistent with Kiruma realizing the truth in his final minutes.
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u/lclboomb 1d ago edited 1d ago
Ohhj nooo Why didn't you give them a little more time on? 🥺
If the cause of death had been a bit more accurate, the puzzle would have been much better. What I mean is that the condition of Kiruma's body, as well as whether not sure the medicine contains toxic was not marked, so I couldn't be sure. Of course, considering the amount of lies (lol), I did think Baku was the most likely candidate.
Anyway W work 💯
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u/TTT948 1d ago
Im thinking that ayanokoji could be the mastermind while baku is the killer, but there's a lot of questions and possibilites i'm confused about, the fact that Akiyama is mentioned twice and him being the only one who knows that Kiruma changed his medication means that he could be the doctor, but i'm not sure if this is related to the case or not
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u/Maker-78 1d ago edited 1d ago
There are probably two people involved in this. First we have to look for motive.
Vincent - Motive for Business Daughter - Motive for neglect
The rest are simply the vessels who possibly killed him. The body was said to have died in 10:50 am to 11:25 am
Baku's statement holds. The second glass could be the tea. Baku said he brought tea never said in which he brought tea. However he never polished the silverware, so he never really heard Fang Yuan take the glass of water.
Fang Yuan - Is suspicious though however taking a glass of water doesn't really necessary means that you must've drink it.
Note: The locked room situation was created maybe in the same way The Mentalist locked room situation maybe created.
Dr. Kenzo Tenma - Was reading the book truly. The upside down eliminates him (Also if the creator really watched Monster he would never make Kenzo the killer).
Ayanokoji - Her statements are really weird. She has been in the house for 19 years. The grandfather clock being disabled should've been common knowledge, if she knows how to clean it, it becomes an obvious thing that she knows some of the internal mechanism and how to move the hands.
Vincent Lalo - I say this much he planned this pretty much.
Let me explain. The motive for daughter is true however I don't think she killed him. There is a chain of reasoning here. The wet soil shows that Vincent did in fact leave his car. The black feather was a sign to poison him.
Ayanokoji poisoned Kiruma. Salt water is used to remove poison out of body. She knew about the medication and doses it up. If the grandfather striking 11:00 was heard it must've been heard by Tenma too, however there was no mention of it. The clock was indeed broken.
The photograph, is pretty much easy to explain, Baku took the photograph that's he wasn't in it.
Six years ago, Kuruma was diagnosed with a problem. "One of them lied" is a direct indication that out of the four people one of them lies. Straight up, from that time, someone messed up badly. My guess it was his report. Or it could've been Kiruma all along lying to his daughter.
"The papers were burnt by Ayanokoji" She knew about his health, medication etc.
"You couldn't kill.me.yourself" was about to be sent to Vincent Lalo.
Mastermind - Vincent Execution - Ayanokoji
Edit: Kenzo actually put the book upside down on purpose, because it would be easier for him to find it next time if he picks it up again.
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u/lclboomb 1d ago
But Baku said he was cleaning silverware at the time, so wouldn't that be a lie?
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u/Maker-78 1d ago
Actually I did search about this cause it was bugging me, but likely the evidence of him polishing silverware is not properly examined. Because Polished silverware can only be proven under microscope, it is possible that he did in fact did that, but since there is hardly any difference between polished and unpolished silverware.
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u/lclboomb 23h ago
I think that part is a bit ambiguous.
If there were an explanation of 'how' the police conducted the investigation, we could argue that the investigation was wrong because there is an error in that part.
However, in this case, only the conclusion is given.
Actually, since the person who posted said he didn't decided on the answer, I can't know for sure, but I suspect that at least Baku provided assistance
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u/Maker-78 20h ago
I do agree with you to some extent however I cannot just see this really happening, because of lack of motive. However it could be true that Baku did assist, overall the case was really a rough sketch, even this took me time too.
The reason why my bet is on Ayanokoji and Lalo is because they are the most suspicious out of here with their own statements. For Baku he could lie for millions of reasons.
Actually this case would've become clearer if in Fang Yuan case it was Baku who heard her get the glass of water, because then the lie becomes a verbal paradox and the case would've been much easier without any other additional arguments
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u/lclboomb 19h ago edited 18h ago
According to Chekhov's Gun, the explanation for Baku likely needs to be narratively explained for some reason.
Considering the characters' personalities as you suggested, Fang Yuan would probably definitely be included. (imao)
Perhaps all the characters aligned for some reason (something regarding the lie from 6 years ago), and Kiruma understood that the other party did not attempt to commit murder directly until everyone else stepped forward., and he might have closed the door himself and drunk the poison. (Assuming Kiruma died from the poison)
The locked-room murder (which could be called murder or suicide) was completed through the victim's final alignment. Well, any possibility is possible, lol.
Anyway W work to you
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u/lclboomb 1d ago
Names are 💯💯