Video · 2026-08-03 · 27m · 6 moments

We tried to out-code Sherlock Holmes

✦ AI generated

timeline · colored by role

Context

The core input on the desk is a string of letters that must be connected as an input, since the desk is covered with letters and sequence numbers.

The team starts puzzling over the letters on Sherlock's desk, wondering why they don't match the expected format and what mechanism connects them to the code's inputs.

transcript

CJ: So, I have an input that I've gotten from his desk that is listed as letters. And if I simply just output it, it says the numbers do not match the provided uh expected format. Now I'm curious about why they don't match the expected format because it is a AGB8 whatever.

Mechanism

The letter moves correspond to chess knight moves, and A-H maps to chess moves on the board, but the connection to the note list remains unclear.

The team realizes the letters relate to knight chess moves on a chessboard, with each column letter possibly representing a move direction, though the exact mechanism to the notes is a mystery.

transcript

Scott: H chess moves is interesting. I was thinking that like Y becomes M and then we'd have to find another one. M becomes what? And it's just like string replacing... There is a chessboard on the main screen and it's just a knight. So these are definitely knight moves, but I don't know how to connect the chess moves to the list of notes.

extends · 1provides context · 1supports · 1

Example

The violin output needs to play a string containing notes A, C, F, and G, connecting audio input on the violin to a matching output.

Scott figures out the violin puzzle by listening to the melody, determining the correct note sequence from the jukebox, which unlocks a new clue: a subway map.

transcript

Scott: So it starts with F... Yes. Nice job, Scott... And that unlocked the floor. There's a new clue. It's a map. A subway map.

extends · 1supports · 1

Data

The cipher encoding described is impossible because it breaks a one-to-one mapping: the same letter maps to two different letters.

The team collates all the letter mappings and discovers an error: B appears twice instead of L, indicating a mistake in reading the butterfly wall mappings.

transcript

CJ: Oh, we have B in here twice. We don't have L... Oh, it's on the wall. Who had the wall? Oh, V goes to L. I have... No, L goes to B... That's on the butterfly wall.

rebuts · 1

Mechanism◆

The output to the puzzle is found by converting the list of moves into a map/replace operation, iterating over the input string and mapping each character to its deciphered letter.

The team writes code that iterates over the recovered string, replacing each character using their assembled cipher map, which decodes to 'Type the name of my worst enemy followed by the number 221.'

transcript

Scott: We have a string separated by spaces. We basically just need to iterate over the string... We'll say the message is split. And then for each character, we'll map it. I guess I could just do a map instead of a for each where we say map at char and then we join that whole thing together. Um, and I'll also add a space in here which just maps to a space. I think I got it for first try. Here we go.

extends · 2rebuts · 1

Claim◆

The final clue was solved by triangulation: the answer station is exactly two stops from Aldgate, four stops from another, and two stops from another, not by decoding a station name.

Scott deduces the final location (Chancery Lane) by triangulating the stop-count distances from multiple starting stations, confirming Claude was slower/dumber than the human.

transcript

CJ: It wasn't an exact letter extraction cipher puzzle. It was triangulation by stop count. Each line means the answer is n stops away from this. So, it was trying to do a cipher of the name of the subway stop... Scott nailed the actual mechanic. Good job.

supports · 1

Highlight slides

Decoding the Puzzle Output✦ from: The output to the puzzle is found by converting the list of moves into a map/replace operation, iterating over the input string and mapping each character to its deciphered letter.The Revealed Message✦ from: The output to the puzzle is found by converting the list of moves into a map/replace operation, iterating over the input string and mapping each character to its deciphered letter.The Final Clue Was Triangulation by Stop Count✦ from: The final clue was solved by triangulation: the answer station is exactly two stops from Aldgate, four stops from another, and two stops from another, not by decoding a station name.Stops: How the Answer Was Triangulated✦ from: The final clue was solved by triangulation: the answer station is exactly two stops from Aldgate, four stops from another, and two stops from another, not by decoding a station name.

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Video · No Priors

The core input on the desk is a string of letters that must be connected as an input, since the desk is covered with letters and sequence numbers.

The letter moves correspond to chess knight moves, and A-H maps to chess moves on the board, but the connection to the note list remains unclear.

The violin output needs to play a string containing notes A, C, F, and G, connecting audio input on the violin to a matching output.

The cipher encoding described is impossible because it breaks a one-to-one mapping: the same letter maps to two different letters.

The output to the puzzle is found by converting the list of moves into a map/replace operation, iterating over the input string and mapping each character to its deciphered letter.

The final clue was solved by triangulation: the answer station is exactly two stops from Aldgate, four stops from another, and two stops from another, not by decoding a station name.

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