The Detective’s DeskLena Moss
Proposed deduction
“The bell rang at 00:05 on Wednesday.”
MEDIUM · CASE FILE
A signal across midnight
Medium · NORTH QUAY RADIO ROOM
A harbour message crossed midnight. Four operators calculated when the receiving bell rang. Find the calculation supported by both station records.
Read the case file below, or open the interactive desk to examine records, keep notes and submit your reasoning. These are the case materials, without the solution.
Your assignment
Midnight and transmission delay. What does the verified record establish?
- The source records are verified. Candidate statements are proposals to test, not additional established facts.
- Use only the rules in this file. There is one supported answer and two decisive proof documents.
People and accounts
Bram Vale
Proposed deduction
“The bell rang at 00:19 on Wednesday.”
Cora Pike
Proposed deduction
“The bell rang at 00:12 on Wednesday.”
Davi Reed
Proposed deduction
“The bell rang at 23:47 on Tuesday.”
Case records
Read each record on its own terms. A claim made by a person is different from a fact established by an independent record.
PRIMARY RECORD
The sending dial
The message left North Quay at 23:54 on Tuesday. This dial was seven minutes fast throughout the shift.
Convert the sending dial to civil time by subtracting seven minutes.
LINKED RECORD
The relay interval
Every message on this line took exactly 18 minutes from departure to the receiving bell. Receiving times use accurate civil time.
Add the relay interval after correcting the dial, including the change of day.
CONTEXT NOTE
The envelope rack
The original paper message was filed in blue rack C after receipt.
The filing rack does not establish when the bell rang.
Questions to resolve
What civil time satisfies the complete record?
Use the interactive case desk to select your finding and cite the records that support it. The answer is checked there, and your progress stays in your browser.
Build your finding
Compare the records with each account. Work out what the evidence establishes, then separate that finding from anything it does not prove.