Clues & Culprits › Archive › Oct 9, 2026 Medium walkthrough
Oct 9, 2026 Full Proof Walkthrough
Every verdict in the Medium case “Two Hundred Lucky Researchers”, 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. 15 of them carry a clue; the other 5 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: Pia (D4) begins the case proven innocent.
Silas and I share the same verdict: both criminal or both innocent.— Pia, salesperson (D4)
Step 1: Silas (C5, intern) is innocent. This follows from Pia’s statement and the verdicts already proven.
Step 2: Raj (B5, coder) is a criminal. This follows from Silas’s statement and the verdicts already proven.
The person between me and Quinn is a criminal.— Silas, intern (C5)
Step 3: Theo (D5, coder) is a criminal. This follows from Raj’s statement and the verdicts already proven.
There is exactly one innocent to my right.— Raj, coder (B5)
Step 4: Omar (C4, office manager) is innocent. This follows from Theo’s statement and the verdicts already proven.
All three of my neighbors are innocent.— Theo, coder (D5)
Step 5: Mila (A4, designer) is a criminal. This follows from Omar’s statement and the verdicts already proven.
Nobody to my left is innocent.— Omar, office manager (C4)
Step 6: Ned (B4, intern) is a criminal. This follows from Omar’s statement and the verdicts already proven.
Step 7: Joan (B3, coder) is innocent. This follows from Ned’s statement and the verdicts already proven.
The person between me and Felix is innocent.— Ned, intern (B4)
Step 8: Arlo (A1, intern) is innocent. This needs 2 statements together — Mila’s and Joan’s. Assume the opposite verdict and at least one of them breaks.
Column B has more criminals than my column.— Mila, designer (A4)
Exactly one of Ezra's five neighbors is a criminal.— Joan, coder (B3)
Step 9: Ezra (A2, designer) is a criminal. This needs 2 statements together — Joan’s and Arlo’s. Assume the opposite verdict and at least one of them breaks.
Exactly two of my three neighbors are criminals.— Arlo, intern (A1)
Step 10: Idris (A3, investor) is innocent. This needs 2 statements together — Mila’s and Joan’s. Assume the opposite verdict and at least one of them breaks.
Step 11: Kira (C3, designer) is a criminal. This follows from Idris’s statement and the verdicts already proven.
There are exactly two criminals to my right.— Idris, investor (A3)
Step 12: Dev (D1, investor) is innocent. This follows from Kira’s statement and the verdicts already proven.
Exactly three of the four people in the corners are innocent.— Kira, designer (C3)
Step 13: Leo (D3, intern) is a criminal. This follows from Idris’s statement and the verdicts already proven.
Step 14: Cal (C1, investor) is a criminal. This follows from Leo’s statement and the verdicts already proven.
Exactly two of the three investors are innocent.— Leo, intern (D3)
Step 15: Hugo (D2, salesperson) is innocent. This follows from Dev’s statement and the verdicts already proven.
There is exactly one innocent between me and Pia.— Dev, investor (D1)
Step 16: Quinn (A5, coder) is innocent. This follows from Kira’s statement and the verdicts already proven.
Step 17: Basil (B1, office manager) is a criminal. This follows from Cal’s statement and the verdicts already proven.
Exactly seven of the fourteen people on the edges are criminals.— Cal, investor (C1)
Step 18: Felix (B2, salesperson) is innocent. This follows from Joan’s statement and the verdicts already proven.
Step 19: Greta (C2, office manager) is innocent. This follows from Ezra’s statement and the verdicts already proven.
Exactly four of Felix's eight neighbors are criminals.— Ezra, designer (A2)
The final lineup
| A | B | C | D | |
|---|---|---|---|---|
| 1 | Arlo innocent | Basil criminal | Cal criminal | Dev innocent |
| 2 | Ezra criminal | Felix innocent | Greta innocent | Hugo innocent |
| 3 | Idris innocent | Joan innocent | Kira criminal | Leo criminal |
| 4 | Mila criminal | Ned criminal | Omar innocent | Pia innocent |
| 5 | Quinn innocent | Raj criminal | Silas innocent | Theo criminal |
What happened
The flaws were planted. Raj and Theo, two senior coders, slipped one small, findable bug into every release, and Ezra, Kira and Mila hid matching hints in the app's design so the right people knew where to look. Leo and Ned, the interns, registered two hundred researcher accounts using two hundred borrowed email addresses. Cal, an early investor, laundered the bounties through his friends' companies, and Basil, the office manager, approved every payment on the afternoon it arrived. Two of the 'researchers' turned out to be Basil's cats.