Clues & Culprits › Archive › Oct 7, 2026 Medium walkthrough
Oct 7, 2026 Full Proof Walkthrough
Every verdict in the Medium case “The Moon Rock Swap”, in an order where each step is proven by the statements already on file.
Play it first Just a hint, please
This Medium case seats 20 suspects on a 4×5 grid. 17 of them carry a clue; the other 3 only have something to say about themselves. 3 of the steps can only be proven by reading two or more clues together. The order below is one valid route; any order where each verdict is proven when you enter it reaches the same answer.
Spoiler: show the full walkthrough
Start: Nora (B4) begins the case proven a criminal.
The person between Amir and Ivan is innocent.— Nora, security chief (B4)
Step 1: Esme (A2, rocket scientist) is innocent. This follows from Nora’s statement and the verdicts already proven.
Step 2: Frank (B2, security chief) is innocent. This follows from Esme’s statement and the verdicts already proven.
There are no criminals between me and Hugo.— Esme, rocket scientist (A2)
Step 3: Celia (C1, billionaire backer) is innocent. This follows from Frank’s statement and the verdicts already proven.
Dexter and I have exactly two innocent neighbors in common.— Frank, security chief (B2)
Step 4: Bruno (B1, security chief) is a criminal. This follows from Celia’s statement and the verdicts already proven.
The person between me and Amir is a criminal.— Celia, billionaire backer (C1)
Step 5: Dexter (D1, billionaire backer) is a criminal. This follows from Bruno’s statement and the verdicts already proven.
There is an odd number of innocents to my right.— Bruno, security chief (B1)
Step 6: Gemma (C2, cleaner) is innocent. This follows from Esme’s statement and the verdicts already proven.
Step 7: Hugo (D2, hacker) is a criminal. This follows from Dexter’s statement and the verdicts already proven.
Exactly one of my three neighbors is a criminal.— Dexter, billionaire backer (D1)
Step 8: Jasper (B3, launch engineer) is innocent. This needs 2 statements together — Gemma’s and Hugo’s. Assume the opposite verdict and at least one of them breaks.
Exactly four of my eight neighbors are criminals.— Gemma, cleaner (C2)
Exactly two of my five neighbors are criminals.— Hugo, hacker (D2)
Step 9: Ivan (A3, launch engineer) is innocent. This needs 2 statements together — Gemma’s and Jasper’s. Assume the opposite verdict and at least one of them breaks.
All the criminals in my row are connected.— Jasper, launch engineer (B3)
Step 10: Kofi (C3, cleaner) is innocent. This needs 2 statements together — Gemma’s and Ivan’s. Assume the opposite verdict and at least one of them breaks.
All the innocents in my row are connected.— Ivan, launch engineer (A3)
Step 11: Lionel (D3, billionaire backer) is a criminal. This follows from Gemma’s statement and the verdicts already proven.
Step 12: Otto (C4, launch engineer) is innocent. This follows from Kofi’s statement and the verdicts already proven.
Exactly three of my eight neighbors are criminals.— Kofi, cleaner (C3)
Step 13: Pia (D4, hacker) is innocent. This follows from Kofi’s statement and the verdicts already proven.
Step 14: Sadie (C5, cleaner) is a criminal. This follows from Pia’s statement and the verdicts already proven.
Exactly one of Sadie and me is a criminal.— Pia, hacker (D4)
Step 15: Theo (D5, rocket scientist) is innocent. This follows from Lionel’s statement and the verdicts already proven.
Everyone below me is innocent.— Lionel, billionaire backer (D3)
Step 16: Amir (A1, hacker) is a criminal. This follows from Theo’s statement and the verdicts already proven.
An odd number of the hackers are innocent.— Theo, rocket scientist (D5)
Step 17: Raj (B5, rocket scientist) is a criminal. This follows from Otto’s statement and the verdicts already proven.
Sadie and I have exactly two criminal neighbors in common.— Otto, launch engineer (C4)
Step 18: Quinn (A5, rocket scientist) is innocent. This follows from Sadie’s statement and the verdicts already proven.
There is exactly one innocent to my left.— Sadie, cleaner (C5)
Step 19: Marco (A4, billionaire backer) is a criminal. This follows from Amir’s statement and the verdicts already proven.
Exactly two of Raj's five neighbors are innocent.— Amir, hacker (A1)
The final lineup
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Amir criminal | Bruno criminal | Celia innocent | Dexter criminal |
| 2 | Esme innocent | Frank innocent | Gemma innocent | Hugo criminal |
| 3 | Ivan innocent | Jasper innocent | Kofi innocent | Lionel criminal |
| 4 | Marco criminal | Nora criminal | Otto innocent | Pia innocent |
| 5 | Quinn innocent | Raj criminal | Sadie criminal | Theo innocent |
What happened
The real rock went up in the world before it went missing. Dexter, Lionel and Marco — three billionaire backers who each wanted a piece of the Moon on their desk — paid for the swap. Raj ground and painted the granite double; Amir and Hugo looped the display-case camera so it showed the same quiet night again and again; and Nora and Bruno, running security, signed the overnight log 'all clear'. Sadie wheeled the rock out in her cleaning trolley, and the backers had it cut into three. The geologist was nine years old.