The Detective’s DeskRui Reed
Event organiser
What happened from your point of view?
I approved Sana’s protection test, not a drainage demonstration.
What should I check to test that account?
Nico had asked to withdraw Mara’s entry after a dispute.
HARD · CASE FILE
The Reservoir’s Two Failures
Hard · A miniature irrigation exhibition
A pump shutdown and a drained reservoir occur close together. Determine which event caused each symptom and whether two technicians agreed to sabotage the show.
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.
The scene
The model is a tabletop exhibit. Supplied tests explain its valves and overload protection; no engineering knowledge is assumed.
People and accounts
Sana Cole
Electrician
What happened from your point of view?
I ran the authorised overload test.
What should I check to test that account?
The automatic trip stops flow; it cannot open the manual outlet.
Evan Moss
Judge
What happened from your point of view?
The water level dropped before the motor stopped.
What should I check to test that account?
I recorded both observations on one reference clock.
Mara Hart
Model designer
What happened from your point of view?
The pump fault drained my reservoir.
What should I check to test that account?
Nico adjusted its outlet while I was away.
Nico Bell
Demonstrator
What happened from your point of view?
I only tested an indicator.
What should I check to test that account?
I turned the outlet selector toward the waste channel.
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.
Case record · Judging desk
Judge’s reference sequence
The reservoir starts draining at 14:03. The pump trips at 14:07, after the level has already fallen.
Case record · Judging desk
Prior withdrawal dispute
Nico’s request to remove Mara’s entry is rejected. The refusal supplies motive, not the mechanical cause.
Case record · Model bench
Demonstrator’s setup entry
Nico alone holds the selector key during 13:55–14:04 and signs that he changed the outlet for a “failed entry demonstration”.
Case record · Control desk
Separate task messages
Nico’s private drainage note is not sent to Sana. The complete test conversation with Sana discusses only overload protection.
Case record · Control desk
Electrical test authority
Rui authorises Sana’s overload protection test at 14:07. It expressly concerns the motor only.
Case record · Model bench
Selector inspection
The outlet is found locked toward waste. Its broken witness seal is from the intact 13:55 inspection.
Case record · Control desk
Electrician’s full work log
Sana remains at the electrical cabinet and follows the approved test. The selector key is never issued to her.
Case record · Model bench
Model test findings
Only the manual waste outlet drains the reservoir. A pump overload trip stops circulation but leaves water stored.
Questions to resolve
Who deliberately directs the reservoir to waste?
Which event comes first?
Who is established as knowingly helping the drainage sabotage?
What explains the 14:07 motor stop?
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.