Case · ID sample-bsi-en · schema v1
The Riddle of the Small Letter
A sample case to get to know the companion
- Introductory
- 60–90 min
- 1–4 investigators
- by JustPlayBo
- EN
- #sample
- #baker-street-irregulars
- #introduction
Also available in: IT · Italiano
The Riddle of the Small Letter
London, a drizzling afternoon. As Watson skims the Times beside the Baker Street fire, a Baker Street Irregular knocks at the door.
“Mr Holmes, Mrs Carruthers sends us. Her husband has not come home in two days, and his private library has been ransacked.”
The investigation begins at the Criterion Club, the last place Mr Carruthers was seen.
Hint: whenever the narration invites you to “circle a letter”, mark it in your notebook — some later clues will only unlock if you have collected the right letter.
Places & clues
Each entry is a zone of the London map. Conditional rows reveal themselves once you have circled the indicated letters.
Point
17SOWestminster Abbey welcomes a few tourists. The custodian points to the chapel of St Edward.
Requires: W
With the letter W — in the pavilion dedicated to Wellington you find recent traces of forced entry and a scrap of dark blue cloth, the same as Mr Carruthers's coat.
Requires: SW
With S and W — behind Wellington's tomb, a hideout contains a diary: Mr Carruthers was held there. Who led him here remains to be uncovered.
Point
3SOAt the Criterion Club the doorman remembers Mr Carruthers: he came in on Wednesday afternoon and never left through the main entrance.
A private member card lies on the floor — it was not there yesterday.
Requires: S
With the letter S — the member card opens a strongbox in the cellar; inside, a map of the Westminster area marked in red ink.
Point
6SOSt James's Palace is quiet. The guards have noticed nothing unusual in the past 48 hours.
Point
8SOAt the Diogenes Club silence is the rule. Mycroft receives you with a nod: “Brother of mine, if you seek a missing man, try circling the letter W.”
Requires: SW
With S and W — Mycroft, without raising his eyes: “Westminster Abbey, Wellington pavilion. Your inquiry ends there.”
Questions
Primary questions
Who is responsible for Mr Carruthers's disappearance? +15
The butler of the Criterion Club.
Where was Mr Carruthers held? +15
In the hideout behind Wellington's tomb at Westminster Abbey.
Which item recovered at the Criterion Club proved decisive for the inquiry? +10
The private member card dropped on the Club floor.
The card opened a strongbox containing the area map.
What allowed Mycroft to point to Westminster? +10
The combination of the S (strongbox) and W (Wellington) clues.
Secondary questions
What colour is the scrap of cloth found at the Abbey? +5
Dark blue.
On which day of the week did Carruthers enter the Criterion? +5
Wednesday afternoon.
Who knocked on the Baker Street door at the start of the case? +5
A Baker Street Irregular, on behalf of Mrs Carruthers.
Which chapel does the Abbey custodian first point to? +5
The chapel of St Edward (a misdirection).
Sherlock Holmes' path
Criterion Club
3SOSpeak to the doorman, spot the member card on the floor, and inspect the strongbox in the cellar.
Letters earned: S
Diogenes Club
8SOMycroft confirms the connection with Westminster; he hints that you should circle the W.
Letters earned: W
Westminster Abbey
17SOFind the hideout behind Wellington's tomb and Carruthers's diary.
Solution
The culprit is the butler of the Criterion Club, who had access to Mr Carruthers's private member card. The circled letters S and W tell the story: S for the Strongbox opened, W for the Wellington recovered at the Abbey.
Author's notes
Onboarding adventure for anyone opening the companion for the first time. It exercises every relevant mechanism of the v1 schema: conditional clues, circled letters, Holmes’s path, and scoring questions. Feel free to duplicate it as the skeleton for your next case.
The full payload is at
data/adventures/sample-bsi-en.jsonand is served verbatim at/adventures/sample-bsi-en/index.json.