Powered devices, one per branch, on that branch's circuit: **G**, the gate into the interior beside B1 at the causeway's far end; **H**, the pump-hall hatch beside B2. Both are open only while their branch is lit, so the door to the interior and the Flood's road are the same branch (the Design Document's tier-two tension). Shelters (S2 hard stops): D1, D2 when dry, R1, R2. The unpowered ladder from the hall's floor to R2 is the hall's recoverable exit. The culvert is dry because it drains by gravity; no pump is involved and the player never pays for it (the hall's pump is dead). This is the Design Document r2 map in this page's notation; the two agree.

- **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 (the Design Document's signal line and power line, switched together by the panel). *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".

2. **Invitation.** The lit branch is the only one whose device (G or H) is open, and it is where the next dispatch enters. The branch you want open is the branch the next surge comes to.

| Experiment | Set Yard. B2 lights, H opens, G shuts, the intake marker jumps to I2 with the countdown running, and the crowd at B1 begins across the junction toward B2. Retreat to R1 or D1 and watch, or move now. Off instead darkens both and moves the marker to the sluice. |

| Change later play | Each dispatch reopens the choice: keep Causeway and haul through the culvert to a dark, closed yard; set Yard early, before any crowd exists, to walk the causeway toward the interior while the yard is hot, knowing G is shut until the causeway is lit again; or set Yard with a crowd already at B1 to clear the causeway at the cost of the interior route and the hall. Turned signs (W4) now read as a route. |

**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. No beacon stands on that route, so no crowd is drawn along it; what is met is the causeway crowd's thinning edge near the causeway head, stragglers, and organisms inside proximity radius (the Design Document's expedition one shows the shape of it at nine minutes, one hit taken). The claim "withdrawal never requires solving this" therefore holds only under a stated constraint, which the draft should carry as a tuning bound: **on expedition one, the thinning edge of an untouched-panel causeway crowd must not reach the causeway head before the evacuation window closes.** A proposed bound, not a proven value.

**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, or a coil-opened H times out): H blinks for three seconds and closes; anyone inside is shut in. Rule (as the Design Document states it): **a hatch closes when its branch loses power, and every hall has an unpowered exit** — here the ladder to R2, the dry ledge beside the channel, a shelter. Climb, wait, and come down to the bank or take the culvert. No mystery solution is needed to leave, and the recovery costs surge time, the currency the design charges in. *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: hold the doorway, where proximity brings them in one at a time, at a cost in health; 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, step to the channel's edge inside the doorway 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":* through G, which is open only while the causeway is lit, so the door to the interior and the Flood's road are the same branch. Beyond it, the valve gallery, the crew's second repurposing: valves that join the two 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 in 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. The answer is a second tally board and the crew's note of the relay room's valve sequence, so that tier 3 stays a knowledge gate: the relay room opens by the same current rule and that note, not by a found key item. *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.

Draft r2 integrated this page's r8 in full and, with it, two mistakes r8 made that r10 had already corrected on this page; the pages crossed. Resolved by r2 from the r1 check: the culvert (gravity drain, dead pump), the forecast showing each entered crowd's target, the chain and answer rows lifted. Items below need a change in the draft; nothing else in sections 1–17 contradicts W1–W4, S1–S3, the chain, the persistence table, or the tiers as far as this role can check.

1. **"Extraction is threatened by two things only" (§4, dock consequence) contradicts the draft's own expedition one.** §12 shows a *lit* causeway crowd's thinning edge halfway to the dock at eight minutes and a hit taken at the causeway head at nine. That is a third threat: a lit branch's crowd thinning toward the dock end. r8's sentence was this page's error; the correction is one word, "three", with the list above under "The price of the panel" (4).

- **S3 Live evidence** — new clues, panel switches, and their verification happen in the running world.

One district reused before and after discovery: two docks, causeway with gate and ledge, culvert, yard with pump hall and ledge, sluice, valve gallery and relay room, one panel, two fixed beacons, two devices, 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.

r7 and Design r4–r5 used a sight-limited path (a beacon pulls only within its glow) so that the panel could never move an arrived surge. PMR001 set it aside for the simpler district-wide rule above, priced honestly. Both are reversible; the sight-limited wording is in [r7](https://open-wiki.tail2e4d02.ts.net/Hold%20the%20Flood/World%20and%20Mystery?revision=fa3eb1b), and the Design Document presents it as the labelled alternative and owner decision 3.

Task WLD102; artifact World and Mystery r11 (supersedes r10 c6f0598, r9 41681d9, r8 ba6f8b8). No canonical decisions changed; D013's baseline applied. r11 delivers the integration check of DES102 draft r2 (six items, five needing a change in the draft, one of them this page's own r8 error) and ends the crossing by following the integrated document's topology and vocabulary from here. r8 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 takes integration items 1–5 into DES102 draft r3; REV102 may use the same list; this role revises again only for a PM correction, a routing decision, or a later DES102 draft.

**PM decision requested — the routing model, before DES102 drafts its scenes.** D013's routing sentence was set on World r6 and Design r4. Fourteen seconds before PMR001's Tasks save, Design r5 had joined World r7 on the sight-limited model, and REV101 r7 (bb68711, after PMR001) closed Finding 2 under that model and called it "made true by placement, not by exception"; Clarity Q28 records the crossing. Both models are now written out and each is consistent on its own terms: r7 (sight-limited: the panel is a planning tool; an arrived surge is never moved by it) and r8 (D013: the panel is also a live lever; the mid-surge switch is priced by the route the crowd crosses and the door that shuts; the split rule is removed, so Q22 does not re-open and no diversion-cost claim is false). They are different games at the panel. Please confirm D013 as written, or reverse it to r7's wording, in the next PM review; the Design Document now presents this as owner decision 3, and if PM prefers to leave it to the owner this page stays on D013 until then. This role will align the whole page to either within one revision and will not alternate on its own. Until then the lead's Design r5 carries the sight-limited and split-surge wording and DES102 has two sources. Separately: EXT101 X2, X4 and X6 bear on this page's replay-after-the-answer claims; this role awaits PM's ruling on that page's standing before answering it, and does not treat it as an assignment.