The Detective’s DeskPEN & PAPER · CASE FILE
Pen & Paper · A tidal dock with two routes
A captain invokes the tide as an alibi after a harbourmaster is killed during a power failure. An electrician calls it a fault, while a fuel thief admits one crime and denies another. Reconstruct usable access and the intended blackout.
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.
Keir dies from a deliberate assault in the office between 21:15 and 21:20. The lower path is submerged, but the dock plan includes an elevated gantry. No vessel departs before police seal the dock.
Shipping agent
I waited at the weighbridge under its camera.
Keir was refusing my client’s departure clearance.
He put the disputed manifest in the office drawer at 21:10.
Cargo captain
I stayed aboard the tug during the dock blackout. I could not cross the flooded lower path.
Harbourmaster Keir held a manifest proving I had concealed unauthorised cargo.
The lower path is not the only route between the tug and the office.
Dock electrician
A breaker tripped at 21:14. I restored power as quickly as possible.
Zara paid my overdue rent last month. She asked for help moving a manifest.
The office’s backup camera has its own battery but shares a recording cable.
Harbour medic
I attended a driver at the gate from 21:08 to 21:25.
Keir had complained about my invoice, but the treatment call was genuine.
The injury report gives a narrower interval than the radio distress call.
Crane operator
I was in the crane cab during the outage. Its battery camera shows the high gantry.
I was due to lose overtime if Zara’s departure was delayed.
I saw Zara cross the high gantry, not the flooded lower path.
Fuel attendant
I was by the lower tanks. I siphoned fuel earlier and do not want that treated as murder.
Keir had caught me taking fuel. He had not yet filed a report.
Zara’s tug gangway meets the elevated gantry, which stays above the tide.
Read each record on its own terms. A claim made by a person is different from a fact established by an independent record.
Physical record · Harbour office
The fatal assault is close-range during 21:15–21:20. No remote device is present. The manifest drawer is open and its sealed folder is missing.
Physical record · High gantry
The folder is found in Zara’s tug locker. Its seals and Keir’s annotations match the missing office record and identify her unauthorised cargo.
Physical record · Fuel tanks
Cal’s fuel theft occurs before 20:50. Its quantity and container explain his separate concealment, without placing him on the office gantry.
Physical record · Power shed
Zara tells Arun, “Keir will not hand it over. I will silence him, take the manifest and use the gantry. Blank the office recording.” Arun replies, “I understand the plan; the cable will be out.”
Physical record · High gantry
The lower path is impassable after 21:12. The high gantry remains dry and connects the tug directly to the office’s upper door.
Physical record · Fuel tanks
Cal remains at the tanks, Iman at the weighbridge, Mara at the gate and Nell in the crane cab during the fatal interval. Their cameras are battery powered.
Physical record · Power shed
Arun signs for the connector key and isolates the circuit at 21:13, before his reported fault. No repair request exists.
Physical record · Power shed
Arun inspected the independent camera battery that afternoon. He knew switching off mains alone would not stop recording.
Physical record · High gantry
Zara’s face and captain’s coat are visible crossing the gantry at 21:15 and returning at 21:20 with a folder. The office door is the only destination beyond the crossing.
Physical record · Power shed
There is no automatic trip. The supply was switched off manually. A recording-cable connector was removed before the outage, disabling the office’s battery-backed footage.
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Compare the records with each account. Work out what the evidence establishes, then separate that finding from anything it does not prove.