Case desk · beginner's brief
Welcome to the desk.
Take the case at your own pace. The only equipment required is a careful eye; a pencil is recommended, especially when the evidence starts behaving like a busy office.
The case in three acts
The following is an original tutorial case, made for this page. It is not a production catalogue case, a mock API response, or a preview of today’s file.
Bombay, 1978 · after the late show
Opening Night
A studio ledger disappears between the last reel and the first cup of tea. Three people stayed behind. The rain was punctual, but it declined to testify.
The short report
At a small cinema office near the harbour, the ledger’s brass key was used after the evening screening. The desk lamp was still warm. No one saw the hand that turned it, but three statements put the room in a manageable state of confusion.
Good detective work begins here: read the setup, open the dossier, and treat every clue as a relationship between one suspect, one place, and one implement.
The three suspects
- Mira DsouzaProjectionist; keeps the visitors book in her own handwriting.
- Rafiq MerchantDistributor’s runner; carries timetables even when nobody asks.
- Tara SenLedger clerk; remembers figures better than faces.
Locations
Apollo Bunder · Grant Road Cinema · Ballard Pier
Implements
Brass key · Fountain pen · Folding umbrella
- 01Mira signed the visitors book at Apollo Bunder.
- 02Rafiq was not at Ballard Pier, and Tara was not at Apollo Bunder.
- 03The fountain pen was at Ballard Pier; the folding umbrella was at Grant Road Cinema.
- Read the report.Start with the setup, then read every clue in the dossier. A definite statement earns the first pencil mark.
- Compare the possibilities.Each suspect has one location and one implement; each location and implement is used once. Keep the separate matrices in step with one another.
- Name the truth.When one who, where, and what remain together, choose them and submit the accusation.
Use the board
The elimination board is your notebook. Cells begin blank (Unknown). Tap or use Enter to cycle: Unknown → Possible → Eliminated → Confirmed → Unknown. The symbols—not only their colours—show the difference, so keep the legend in view.
Which grid? Use suspect × location for a place clue, suspect × implement for an object clue, and location × implement when the clue links two places or objects. The board does not fill deductions automatically; mark the other row and column cells yourself.
The pencil rule
Start with definite statements. If a clue says a character cannot be in a location, eliminate that cell. A firm match also eliminates the other options in its row and column. This is why Mira’s single signature does more work than a paragraph of suspicion.
Step one
Fix the one thing the clerk saw
Mira signed the visitors book at Apollo Bunder. Confirm that cell, then cross out her other two locations. A confirmed location is not a mood; it closes the row.
| Suspect | Location | Implement | ||||
|---|---|---|---|---|---|---|
| Apollo Bunder | Grant Road Cinema | Ballard Pier | Brass key | Fountain pen | Folding umbrella | |
| Mira Dsouza | ||||||
| Rafiq Merchant | ||||||
| Tara Sen | ||||||
Step two
Let the empty squares do their work
Rafiq was not at Ballard Pier, and Tara was not at Apollo Bunder. Apollo is already Mira’s, so the remaining places settle: Rafiq at Grant Road Cinema, Tara at Ballard Pier. The city has supplied a seating plan.
| Suspect | Location | Implement | ||||
|---|---|---|---|---|---|---|
| Apollo Bunder | Grant Road Cinema | Ballard Pier | Brass key | Fountain pen | Folding umbrella | |
| Mira Dsouza | ||||||
| Rafiq Merchant | ||||||
| Tara Sen | ||||||
Step three
Carry the evidence across
The fountain pen was at Ballard Pier and the umbrella at Grant Road Cinema. That confirms Tara with the pen and Rafiq with the umbrella. The brass key is the only implement left for Mira.
| Suspect | Location | Implement | ||||
|---|---|---|---|---|---|---|
| Apollo Bunder | Grant Road Cinema | Ballard Pier | Brass key | Fountain pen | Folding umbrella | |
| Mira Dsouza | ||||||
| Rafiq Merchant | ||||||
| Tara Sen | ||||||
Make an accusation
Filed after the late show
Who: Mira Dsouza
Where: Apollo Bunder
What: Brass key
That is the completed accusation in this fictional example. In a live case, select a culprit, location, and implement, then submit the accusation. Some harder cases also ask for the motive—Why?—as a fourth selection. A wrong answer is recorded; revisit the clues and use the next attempt only when your logic is ready.
The board did not need a confession. Once the alternatives were crossed out, the answer had the courtesy to remain.
Detective tips
- Read “either/or” clues carefully.They often rule out more than one option.
- Use hints only when you want a nudge.They are optional; a clean deduction is its own small reward.
- Play as a guest or choose optional sign-in.Either way, the case is the same.
- Need a hand with the interface?Visit Accessibility or Support.