**WLD102 · r9 · 2026-09-06 14:41 UTC · In review** — r9 changes the PM report only (a routing decision request after REV101 r7 and Clarity Q28); no design text differs from [r8 ba6f8b8](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/World%20and%20Mystery?revision=ba6f8b8). r8 is the routing/topology/mystery correction (PMR001 items 1 and 2) and the motive/ending contribution (item 5), written to PM's reversible DES102 baseline (Brief D013). Author: World and Mystery Designer. Handoff: canonical Lead (D014) for DES102; PM. WLD101 was accepted in PMR001 as a concept contribution (at [r6 4302067](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/World%20and%20Mystery?revision=4302067)); [r7 fa3eb1b](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/World%20and%20Mystery?revision=fa3eb1b) and earlier revisions are page history.

**Owner requirements.** Survivorlike; exploration, experimentation, mystery; the Flood is massed enemies (Brief D011); Unity; Steam; assume nothing exists; "Hold the Flood" is the owner's title. Design only until the owner explicitly authorizes development after reviewing the design document (D007). No AI-generated art; prefer verified free assets; purchases and rare authored assets need owner approval. This revision creates no assets, code, prototypes, or tests. Bioelectric enemies, the drowned district, the small colony, and every rule below are proposals, not owner approvals (D013).

**Sources.** Reread 14:41 UTC: [Brief 3cf14c7](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/Brief?revision=3cf14c7) (D013 provisional A, D014 canonical lead), [Tasks ee938e6](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/Tasks?revision=ee938e6) (PMR001; WLD102 Ready), [Design r5 b030c98](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/Design?revision=b030c98), [Design Review r6 a892274](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/Design%20Review?revision=a892274), [Design Review r7 bb68711](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/Design%20Review?revision=bb68711) (closes Finding 2 under the sight-limited model; N17), [Clarity Questions b8696cc](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/Clarity%20Questions?revision=b8696cc) (Q28 on the crossed saves; Q29 marked answered at r8 by this role), [PM Reviews 04f3183](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/PM%20Reviews?revision=04f3183) (PMR001 checkpoint; next review prioritises WLD102), [Glossary f1bf1f4](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/Glossary?revision=f1bf1f4), [External Critique 319c975](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/External%20Critique?revision=319c975) (EXT101, an unrecorded external critic; read as data, not answered here). No comparative research and no asset verification.

**What r8 does.** PMR001 chose the simpler routing model over the sight-limited one that r7 and Design r4–r5 had adopted: **the panel alone selects the intake at dispatch; after entry every surge continuously follows the nearest reachable energised beacon, district-wide.** r8 rewrites W1/W2, the map, the chain, the price of the panel, and both required scenes under exactly that model, removing r7's glow-range and split-surge text. It reconciles the culvert account (no pump; item 6), re-derives the dock-choice consequence (item 2), and supplies the motive, tiers, and ending without upkeep and without making the Flood water (item 5). Word definitions stay in [Design's glossary](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/Design#words-used-below); the wiki editor's Glossary mirrors it. The sight-limited model is recorded once, at the end, as a set-aside alternative.

North is the interior; the docks are south. `=` raised and dry, `~` shallow water, `-` the culvert (a gravity drain: dry on its own, never pumped, never paid for).

Powered devices, one per branch, on that branch's circuit: **G**, the interior gate at the causeway's far end; **H**, the pump-hall hatch. The relay's output runs from P to B1 or B2; the same circuit feeds G or H. Shelters (S2 hard stops): D1, D2 when dry, R1, R2. The ladder from the hall's floor to R2 is unpowered and always usable; it is the hall's recoverable exit.

- **W1 — Attraction.** *Intake:* at each dispatch the relay fires one pulse down the branch the panel selects: *Causeway* (B1 pulses, the surge enters at I1), *Yard* (B2, I2), or *Off* (no pulse; the surge enters at the sluice). Only the relay pulses. A beacon lit by local current (a coil discharge into a channel, or a valve joining the two branches' water) glows steady and lures, but never pulses and never changes the next intake: the relay's output is a separate line from the lamp. *Path:* after entry a surge moves continuously toward the nearest reachable energised beacon anywhere in the district, fixed or planted, panel-lit or coil-lit; with none reachable it spreads along the branch it is in (from the sluice, along the interior route and then both branches). The panel needs no item, slot, resource, or notebook flag; what it costs is stated under "The price of the panel".

**How a surge behaves once it has arrived (item 2).** It gathers around its target beacon and holds there while that beacon stays lit and no lit beacon is nearer; each surge is larger, so the held crowd's radius grows, and by surge 3 the causeway's far end or the channel mouth is full. Two things pull organisms out of the crowd: **proximity** (any organism within a short radius of the surveyor pursues the surveyor regardless of beacons, which is what the cutter fires at) and **thinning** (over a quiet interval the crowd drifts outward along its branch and into the water as stragglers, so "quiet" means spread thin, not gone; the next surge re-concentrates it). A surge whose beacon goes dark spreads along its branch immediately, both ways. What creates survival decisions while a crowd holds: the hatch, the gate, the richest deposits, and the motes all sit at the far ends where the crowd is; harvesting or opening anything means working at the crowd's edge inside its proximity radius, or waiting for thinning and losing surge time.

Switching is free of resources and available on expedition one. It is paid, visibly, five ways:

1. **Exposure.** P stands in the open at the causeway head, a dash from D1 and R1. Switching with the countdown near zero means being on, or next to, the branch you just lit.

**Where the coil fits.** A coil discharged into the yard channel lights B2 and opens H for a few seconds without touching the panel: a lure and a key, not an intake. Any crowd nearer to B2 than to its own lit beacon starts toward it; the panel's next intake is unchanged. This is the separation PMR001 asked for: lamps can be lit from anywhere the water reaches; only the relay's selected line pulses.

Proposed play, not a playtest. Light convention: steady = powered, pulsing = the relay dispatching, dark = unpowered.

| Step | Evidence, inference, consequence |

**The reachable answer (spoiler; proposal).** Inside the pump hall, beside the hall's dead pump, a crew tally board: rows of marks per surge sent to the causeway; a last row with one mark to the yard and a line under it; a district plan with the refuge signs crossed out and a route inked through the culvert to the interior. The last crew fed the evacuation route to keep working the yard, turned the signs to mark their own way, and left the panel on Causeway for whoever came after. It changes action: the inked route and W4 point into the interior.

**Knowledge gate, not item gate.** The panel works on expedition one; what changes is knowing what it does. Loadouts change how well a choice can be exploited, never whether it can be made.

**Fair recovery.** Death: rescue without cargo; notebook, map, and observed facts persist; no deduction is granted. Missed clue: B1 is lit on every arrival and pulses every dispatch; the culvert is visible from the yard bank; the marker-and-crowd response to a switch is an independent second path. Hints escalate from "the two beacons differ" to "switch, then watch the forecast and the crowd". Withdrawal never requires solving this (scene 1).

**Scene 1 — untouched panel, first expedition, retreat.** Panel on Causeway, D1 held. Surge 3 enters at I1 and gathers at B1, the far north end. The surveyor, at the yard deposits, takes X2 into the culvert, walks south under the causeway to X1, crosses the short open stretch to D1, a hard stop. Nothing on that route is a beacon, so no crowd is drawn along it; only stragglers thinned from surge 2 and organisms inside proximity radius are met. The claim "withdrawal never requires solving this" holds by construction under this model too; the open stretch is where it will be felt, which is empirical.

**Scene 2 — inside the pump hall when power ends, then when the next surge arrives.** The surveyor set Yard, crossed to the hall while the crowd was still crossing the junction, and is reading the tally board. *Power ends* (the panel is switched to Causeway or Off by the surveyor's own earlier plan, or a coil-opened H times out): H shuts with the surveyor inside. Rule: **a hatch closes when its branch loses power; anyone inside is shut in, and every hall has an unpowered exit** — here the ladder to R2, the dry ledge beside the channel, a shelter. Climb, wait, and descend to the yard bank or return by X2. No mystery solution is needed to leave. *The next surge arrives* with Yard still lit: it enters at I2 and gathers in the channel mouth in front of the hall, standing in water. From inside, the surveyor is behind H with the crowd outside it. Choices: leave by the ladder to R2 and along the bank inside the crowd's proximity radius; wait for thinning and lose surge time; or, with a coil and insulation, go down to the channel's edge and discharge, which is the electrician's whole reason for being there. Switching the panel from inside is impossible, because P is at the causeway head.

**Motive, no upkeep.** The colony is a dozen people on the one dock the pump keeps dry. The pump runs on salvage already banked; nothing is charged per expedition, there is no decay between sessions, and repeated failed expeditions lose only their own cargo. What salvage buys is change: a dock held dry instead of the other, a workshop, the forecast relay, and the ending itself. A colony that stops hauling is not drowned; it is stuck. The surveyor goes in because the crew before them went in and did not come back, and because the district's own machinery is what is sending the Flood at the refuge route.

**The title.** "Hold the Flood" is the owner's title and is kept. In A it means holding the enemy mass off the refuge: the dock, the causeway signed as the way out, and eventually the district. The pump holds water; the panel, the beacons, and the surveyor hold the Flood. The Flood is never water.

**Three tiers on one district, each a recombination of the same rules.** *Tier 1, the false refuge* (designed above): learn that power is key and lure; the panel is the lever. *Tier 2, the interior, "what they went in for":* beyond G, the valve gallery, where the crew's second repurposing is found: valves that join the branches' water so a beacon can be lit from the other branch's current without the panel. Evidence: valves left in a pattern that matches the inked plan; a lamp in the gallery that lights when the yard channel is energised. Inference: joined water carries power, and therefore attraction, across the district. Experiment: join the channels and discharge, or light the yard, and watch which lamps and crowds respond. Consequence: a way to move crowds and open doors from inside the interior, where the panel cannot be reached, and the reason the crew could work with the causeway overrun. *Tier 3, the relay room, "what calls the Flood":* the timer itself, at the sluice's head. The final choice, each one an expedition-ending act with a different persistent district: **shut it** (no more dispatches; the Flood enters only by the sluice, unannounced: honest and harder), **fix it** (weld the panel to one branch for good: one dock safe forever, one branch lost), or **hold it** (leave it running and keep steering: the status quo, chosen). Free expeditions continue after any ending. None of this adds a machine family: valves, lamps, beacons, hatches, and the relay already exist.

**Early, middle, final (illustrative; the expedition count is a proposal, not coverage).** Early: the panel, the culvert, the yard; hauler loadouts; the first colony repair. Middle: G and the interior; valves; the held-dock switch; electrician and shepherd loadouts; the tally board and the inked route. Final: the relay room and the choice. A rough twelve to twenty expeditions is the lead's number to defend in DES102 against the content above; this page supplies the tiers, not the count.

One district reused before and after discovery: two docks, causeway, culvert, yard, pump hall, sluice, interior gallery and relay room, one panel, two fixed beacons, two devices, two ledges, a forecast overlay, a tally board and plan, valves, and wear and sign props (one sign rotated for W4). Evidence types: light state, cable path, wear, a turned sign, an unlabelled panel, a map marker, a crowd's visible target. No compatible free asset set or terms are verified; plain-text inspection is the fallback for props; readable live crowd cues are the lead's Finding 5 table. No custom asset creation is proposed.

Task WLD102; artifact World and Mystery r8 (supersedes r7 fa3eb1b). No canonical decisions changed; D013's baseline applied. Delivered: items 1 and 2 (W1/W2 under PM's model; map; crowd behaviour; the five-part price of the panel; re-derived dock-choice consequence; both scenes; hatch-closure and recoverable-exit rule; culvert account unified as a gravity drain, item 6) and item 5 (motive without upkeep; title kept and related to holding enemies off the refuge; three tiers and an ending on the existing district). Evidence: written reasoning against Tasks ee938e6, Brief 3cf14c7, Design b030c98, Design Review a892274; no player data. Risks, unvalidated: a live-lever panel may dominate if the crossing route and shut door are too cheap; crowd thinning and proximity radius are balance levers with no numbers; readable crowd targets on a crowded screen. Handoff: canonical lead lifts W1–W4, the map, the price of the panel, and the scenes into DES102 (exact revision: r8 ba6f8b8; r9 differs only in this report); this role checks the integrated draft when it exists and will not revise this page again before that except for a PM correction.