Object register
Notebook and cipher
Confirmed: the archive records a notebook-and-cipher trail connected to James’s disappearance.
Not confirmed: who created every element, who was meant to receive it, and whether possession proves ownership.
Reference file · evidence boundaries
Research ledgers
Compact registers for the long mystery and the programme’s puzzle logic, designed to show exactly where a fact ends and an interpretation begins.
Reviewed 18 September 2026 · Sources & corrections
Long case
James indexes
Confirmed connection is not proof of authorship, ownership or intent.
Place register
Three verified spheres
- Story Cambridge: James’s police and family life are based here.
- Police station: his professional role and John’s substitution connect the long case to weekly investigations.
- Domestic sphere: Lucy’s search begins from the family consequences of his absence.
Filming geography remains separate from story geography.
Communication register
Material trail, sender open
- Notebook
- Traceable object; authorship and intended reader remain evidence-gated.
- Cipher
- Structured information; meaning does not establish who encoded it.
- Reported speech
- Evidence that words were reported, not automatic proof that the report is true.
Theory control
One confidence scale
Applied to theories, not to personal preference.
UnsupportedNo traceable evidence yet.PlausibleCompatible with evidence but dependent on assumptions.SupportedMultiple independent observations point the same way; alternatives remain.ResolvedBroadcast canon confirms or disproves the proposition.
RuleConfidence can move both ways.Every theory must list supporting evidence, conflicting evidence, assumptions and the next fact that would change its rating.
Case audit
Fair play and viewer solvability
A rubric, not a score guessed from a synopsis.
1 · PresentWas it shown?The clue must appear before the explanation.
2 · LegibleCould it be noticed?Framing, wording or layout must make the information available.
3 · UsableCould it be interpreted?The viewer needs enough context to test the clue.
4 · SufficientCould it narrow the case?A decorative detail is not automatically a solvable clue.
5 · SpecialistWhat knowledge is needed?General observation, taught rule, expert knowledge or external lookup.
LabelSolvable / partial / withheldApplied only after a published-source review.
Viewer-solvability labels
- Solvable: enough visible information exists to reach the central inference.
- Partly solvable: the mechanism can be suspected, but a decisive fact arrives later.
- Withheld: the solution depends on information unavailable before the reveal.
- : the episode has not had a published-source clue-order review.
Specialist-knowledge tags
- General observation: sequence, position, identity or contradiction.
- Taught in episode: a rule explained clearly enough to use.
- Domain expertise: professional, sporting, musical or technical knowledge.
- External lookup: information the episode does not supply.
No episode receives a final fair-play judgement until clue order and the solution chain have been checked against a stable copy.
Reasoning guide
Common deduction mistakes
Use these as rewatch checks.
Treating a label as fixed
A name, room, object or identity may have been assigned rather than proved.
Combining separate accounts
Two memories do not become one reliable clock merely because they agree.
Skipping an interval
Check whether every claimed movement can fit the available time.
Mistaking a partial view for a complete record
Cameras, witnesses and doorways preserve angles, not omniscience.
Using knowledge the episode never supplied
Separate an expert character’s inference from what a general viewer could know.
Preferring a neat motive to stubborn evidence
A satisfying explanation still has to account for the physical record.
Plain-language glossary
Logic and deduction terms
Short definitions for first-time solvers.
- Alibi
- Evidence that a person was elsewhere when an event happened. Time + place
- Constraint
- A rule that limits which answers or movements are possible. Eliminate
- Contradiction
- Two claims that cannot both be true in the same conditions. Compare
- Corroboration
- Independent evidence supporting a claim. Confirm
- Deduction
- A conclusion that must follow if the stated premises are true. Infer
- Inference
- A reasoned interpretation that may still have alternatives. Interpret
- Red herring
- A detail that draws attention toward an unhelpful explanation. Misdirect
- Sightline
- What can be seen from a particular position. Viewpoint
- Timeline
- An ordered record of events and intervals. Sequence
- Working hypothesis
- A provisional explanation tested against new evidence. Test
TermMeaningUse
Character ledger
John’s adjustment to police work
Role changes only; scene-level claims remain in episode files.
Substitution
John enters the station as James to obtain information and becomes involved in a real case.
Repeated case work
The short-term disguise becomes an ongoing way to investigate while his puzzle methods prove useful to the team.
Impersonation boundary changes
The original disguise reaches its crisis point; detailed mechanics stay behind the episode spoiler boundary.
Official consultant
John returns to case work in an acknowledged Crime Scene Consultant role rather than relying solely on James’s identity.
Acceptance gates
Secondary evidence enters the archive by record type
A plausible claim is not enough: each record type has a minimum receipt and a stated non-claim.
Record typeMinimum evidenceWhat it does not prove
Brief landmark or businessChecked episode and timestamp, legible identifier, and a location or company identity cross-check.Endorsement, permission, or story-world ownership.
Trailer versus broadcastDated official trailer, identified shot, and the exact broadcast edition checked at a matching story point.That an absent shot is a deleted scene or was ever in a final cut.
Deleted sceneOfficial release metadata, a rights-holder publication, or attributable named-creator confirmation.A scene inferred only from trailers, continuity gaps or memory.
Episode reviewCritic, publication, publication date and explicit episode scope.That a recap is criticism, or that a series review covers every episode.
Character comparisonAt least two checked scenes recorded against the same contribution, address, object, entrance or relationship field.Private motive, trust or symbolic intention not stated in the evidence.
Negative findings“Not verified” is a result, not an invitation to fill the gap.The ledger records searches and missing evidence so absence is not quietly converted into fact.