Hold the Flood — The Head-works

CAM101 · r4 · 2026-09-06 · Campaign and District Designer · In review; proposal. Nothing here is an owner approval or tested behaviour. r4 works against the ratified shared contract Power and Attraction r3, which closes this page's open dependencies: REV104-1, -3 and -4 are now rules, D024's Answer A is the provisional mystery, and the contract specifies Stop as a gradual failure rather than the instant one r3 wrote, and puts a switch-house in this district. §2 adds the switch-house, §4's Stop row is rewritten to the ratified cascade, and §7's Answer A entry follows. The Collector's water level under Stop — assigned to this role by the contract — is answered on The Collector r4 §7 and summarised here. Walker naming adopted from PMR005. r1–r3 are in page history.

District 7, the last, of the seven recommended on Districts. The Head-works is the World designer's example district (World and Mystery 7699de), placed in the lead's campaign (DES104 §2) and marked "Sketch — not designed" in that page's coverage table. This page writes its ground, its approaches, its decision and its consequences to the standard of DES104 §3.

What this page deliberately does not do: it does not answer the campaign's question. The World designer holds two candidate answers for the owner and the lead recommends one in DES104 §10.7. This page is built so that either answer can be dropped into it without redesigning the district, and §7 says exactly what each answer costs here. That is my job as the place's designer; choosing between them is not.

Sources: Campaign / DES104 r1 (§1–§2, §3.3 for the Barrier's dry dock, §4 modules and roles, §5 the boat's range, §6 the mystery thread, §7 coverage, §10 decisions) · World and Mystery 7699de (the campaign question, the six-part contribution rule, the fixed contract, the head-works sketch, the two answers) · Design Document ec1b6c §3–§4, §11 (the relay room's shut / fix / hold, which this district is the scaled version of) · Design Review 80a882 REV104-1, REV104-4, and the open note that the head-works' clue has no second form · Expansion Brief cdc0c5. Neighbours: Districts · The Collector · Pumping District · Design Index · Glossary.

1. The problem

Every district so far has let the player set where the Flood goes, which district can be read, or how much of it arrives. The head-works is the only place that sets how often, and it sets it everywhere at once and permanently.

That is the whole design problem of a finale in this game: it must be the same kind of decision the player already made in the relay room on expedition ten or eleven, at a scale where they can see it land on every district they have learned. It must not be a new machine, a boss, or a key. It is the relay's lever with more positions and a city on the other end.

The second problem is that the player arrives here having permanently changed four or five districts already, in a state of their own making. The head-works must read differently depending on what they did, or the campaign's persistence was decoration. §5 is how.

2. The ground, and two ways in

                          THE RESERVOIR  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                 |                                  |
                            THE WEIR  ═══════════════════════   spill channel
              (boat route arrives here, from below)                 |
                                 |                                  |
            ┌── RACE HEADS ──────┴─────────────────────┐            |
            |     four gates, one per race, hand-worked|            |
            |                                          |            |
   THE GOVERNOR GALLERY  (dry, raised)  ── THE TALLY ROOM (optional; §6)
            |    the governor: the brake, the cadence lever, the district clutches
            |
   (race route arrives here, from the side, up the Collector's head race)
            |
   ══ MAINTENANCE WALK ══ down to the LANDING (colony-held dock; a shelter)
            |
   BEACON h1 (weir end)      BEACON h2 (gallery end)      PANEL: h1 / h2 / Off
   SLUICE-EQUIVALENT: the spill channel, where the Flood comes in with the overflow

• The reservoir and the weir. Still water above, flowing water below: the races that turn every district's drum start here. Flowing water conducts exactly as any water does — PMR004 is right that r1's wording generalised a local fact into a rule, and r1's sentence is withdrawn. What is true is topological, not hydraulic: nothing electrical is connected to the races, because every powered line in this district stops at the gallery, which stands above the weir on dry ground. That is the dry break, and it is visible — the cable runs end at the gallery wall and no conductor crosses the weir. So the races carry no charge for the same reason the pumping district's relay feed carries none: not because water in motion is special, but because nothing energises it. Anything that did reach a race would energise it normally, and that is a live hazard at the weir, not an exception. Where this district's own power comes from: the trunk, up from the districts below, which under D024 is charge harvested from the Flood — so the gallery's lamps and the gate motors are running on what the player has watched the Collector's meters count all campaign.
• The race heads. Four hand-worked gates, one per race. They are not the finale's decision; they are the local puzzle (§3).
• The governor gallery. Dry, raised, and the only dry ground in the district. The governor stands in it: a brake, a cadence lever with more positions than any panel, and district clutches on the shaft.
• The switch-house, added by the shared contract r3, which places the city's store of harvested charge here and runs the thick cables out to every district's panel from it. It sits below the gallery, off the maintenance walk, and it is where the campaign's biggest fact is legible in one view: every lamp, hatch and beacon the player has used all campaign is running off a store filled by the Flood. The store's level is on a gauge, and it is the only gauge in the game that reads the whole city at once. It is not a lever — the player cannot spend the store — which is deliberate: this district's lever is the governor, and a second one here would make the finale a control room.
• The tally room. Optional; §6.
• Two fixed beacons and a three-position panel, on this district's own circuit, permitted by the trunk exactly as everywhere else — with one consequence the player will notice: this district's own dispatch is set by the lever they are standing next to.

Two ways in, either sufficient.

• The boat route (DES104 §5): the colony's boat range, unlocked from the Tidal Barrier's dry dock, which requires shutting the barrier gates. Arrives at the weir, from below and wet. The approach is a conduction problem — the reservoir's water is the first thing met and everything the player knows about joined bodies applies.
• The race route (mine; see The Collector §7): up the Collector's head race, walkable only while that district is held at level 0 — every gate open, nothing accumulating. Arrives in the gallery, from the side and dry. The approach is a timing problem — the race floods behind each dispatch, so the window is between them.

Why two. A player who bounced off the Barrier is not locked out of the finale, and neither is one who never mastered the Collector; the structural redundancy WLD103 rule 5 asks of clues holds for the road too; and the second approach is the best piece of optional content in the campaign, because it shows the half of the district the first route did not.

3. The local machinery problem: reaching the gallery

The gallery is dry and raised, and the governor is in it. Getting to the governor is the district's own puzzle and it is deliberately a recombination, not a new machine: the gallery door is a device on the gallery's line, and the gallery's line is fed from whichever race is running.

• Four races, four gates. Closing a race's gate stops that race, and with it the drum it drives in the district downstream — the drain-valve R lesson from the pumping district's relay room, at four times the size.
• The gallery's line runs off the race the player leaves open. So the door opens, but which race is running decides which of the district's two beacons is live and therefore where every crowd in the district walks while the player works.
• The decision. Leave the weir race open and the gallery door opens with h1 live: the crowd holds at the weir, across the route the boat route arrived by. Leave the spill race open and h2 is live: the crowd holds at the gallery end — where the player is going. Close all four and the door is dead, but nothing is lit anywhere and the crowd spreads through a district with two dry approaches and no lure at all.

There is no free option. The player is choosing which of their two ways out to give away, which is the pumping district's price of the panel with the stakes made literal, and it is the last time the campaign asks that question before it asks the big one.

4. The decision: three positions, and what each does

r1 offered Slow, Stop and Keep. PMR004 item 3 is right that this was three positions doing two things: a freely adjustable Keep can already wind the cadence back and put it forward again, so Slow was a strictly worse Keep wearing its own name. Slow is withdrawn and merged into Keep. What is left is the relay room's three shapes at city scale, which is what this district was always for: stop it, take it, or leave it.

Why these three and not a boss. They are the three shapes the player already chose between in the relay room, which means the finale is legible to anyone who has been paying attention and needs no tutorial at the worst possible moment. And they leave genuinely different games afterward, which is what the pumping district's endings table already promises at district scale.

Deferral. The choice can be deferred, exactly as the relay's can. Reaching the gallery and leaving without touching the governor is a complete expedition and is not the same as choosing Leave, which is recorded; the district stays open either way.

5. What the player's own campaign has already done to this district

The head-works reads differently depending on the state the player arrives in. r1 claimed the two approaches shut each other off, and that was wrong: it had a starved Collector running fuller, which contradicts The Collector §7, where starvation puts that district a level lower. PMR004 §1 asks the two pages to be reconciled, and this is the reconciliation: shutting the Tidal Barrier makes both approaches to the finale easier and costs the Collector its whole function. That is the trade, and it is a better one than a fake exclusion.

• If the Barrier is shut — which is what unlocks the boat route at all — fewer bodies are in circulation, so the Collector sits a level lower and its head race is walkable more often, not less. Both roads up are open. The price is paid at the Collector, which is no longer a bank: held masses thin, the harvest that funds its two local sinks dries up, and the ways-on withhold less. A player who wants the Collector to keep working arrives here by race, with the Barrier still open, and does the harder version of both.
• The head-works' own supply follows the same rule. With the Barrier open and the city at full circulation, this district's surges are at their largest and the gallery's stationary work is at its most dangerous. With the Barrier shut, they are thin. So the campaign's last district is easier for a player who has spent the campaign's most valuable district to get here — which is the shape I want, because it means the difficulty of the ending is something the player chose four expeditions earlier and can see written on the refuge board before they launch.
• A district darkened at the Exchange cannot be read from the gallery: the governor's board shows a position with no cadence on it. It is the last and clearest statement of what the bank has been doing all campaign.
• The pumping district's relay, if the player shut it on expedition eleven, shows here as a clutch already disengaged — the first thing they ever did to the network, seen from the place that owns it. It costs no content at all and it is the best moment this district has.

6. Discovery

Local question: who oiled this? Every machine in the campaign is seized, silted, weathered or dead. The governor is not.

• Notice. Fresh grease on the governor's shaft. A tally board in the gallery with a recent date. A cadence set to positions no evacuation would ever need.
• Compare. The player has been reading tally boards since the pump hall. Every other one stops at the evacuation. This one does not.
• Infer. The network is maintained, not merely running. That is the answer to the campaign question's second half — and for whom — in the only form this district can honestly give it before the owner has chosen between the two candidate answers.
• Act. The governor, §4.
• Recovery if missed. The grease and the board are in the gallery, which is the only way to the governor, so a player who is only trying to finish the game walks past both.

The redundant form, which REV104 records as missing and which I owe as this district's designer. My proposal, for the World designer to accept or replace: the Lock Flight's lock levers are greased and free, while every other hand-worked mechanism in the city is seized. The player has been pulling those levers since district two without a thought, because a lever that works is not evidence of anything until you have seen a city where nothing else does. It costs no asset, no room and no new interaction, and it pays off five districts later. If the World designer prefers a different second form, this district loses nothing by taking theirs.

The optional tally room. A room off the gallery, never required, holding the maintenance boards for the whole network: which district was serviced, when, and in what order. It is where a player who wants the campaign's bookkeeping can have it, and it is the natural home for whichever of the two candidate answers the owner chooses. Its contents are the World designer's to write.

7. What each candidate answer costs this district

Stated so that the decision in DES104 §10.7 can be made with its consequences visible. I do not recommend between them; that is the World designer's and the owner's.

• Answer A, the machine. Costs this district nothing new. The grease is the works' own automatic maintenance, the tally room's boards are printed by the machine, and Stop ends the harvest, so the store drains and the city goes dark district by district, the colony's pump included, as §4 now states in full on the contract's ratified cascade — which makes the finale's cost enormous and entirely mechanical. It also settles REV104-4: the districts' circuits are fed by charge harvested from the Flood, which the Collector's meters have been telling the player for two districts.
• Answer B, the keepers. Costs this district one human presence and a reason — an asset category this design has otherwise avoided completely, and the campaign's only character. It changes Keep from "the player takes the job" to "the player takes it from someone", which is a stronger scene and a different game. It leaves REV104-4 unanswered, so the grid's power source would need stating elsewhere.

The one thing I will say as the district's designer: whichever is chosen, the three governor positions in §4 stand unchanged. That is the property I built the district for.

8. Enemy and build pressure

Roles are the six the Combat and Enemy Designer defines in CMB101; shared rules on Combat Rules. Campaign owns placement, Combat owns behaviour. Everything below works with the Walker alone (the base role, renamed from Drifter for coordination under PMR005).

• The only district with still, flowing and absent water in one map, so it is the one place a rack cannot be specialised. The coil works at the weir and in the spill channel and nowhere in the gallery; insulation matters below the weir and not above it. A player who has carried a district-specific rack all campaign has to build a general one for the first time, which is a fitting last exam and is a stated cost rather than a difficulty tint.
• The gallery is the campaign's longest stationary interaction, because the governor's positions take time to set. That is what makes the Carrier the right body here: a player who arrived by the weir carrying batteries for it is carrying exactly what a Carrier walks to, and the counterplay — spend it, or decoy it with a planted battery — has to be decided before the lever is touched, not during.
• Grounders are the district's own argument against complacency. They ground a powered cable run and darken its beacon; here the run that feeds the gallery is the one the player chose in §3, so a Grounder can close the gallery door behind them. Placement proposal for Combat: at most one, and only after the player has set a race — the threat should be that a plan expires, not that the finale is arbitrary.
• Anchors on the weir apron and Crusts in the spill channel are the two that make the wet approach a different problem from the dry one, without either approach needing a role the other does not have.
• Sparks are the reason the weir approach is not simply the easy one. Killing in the reservoir's shallows energises connected water for a moment, and at the weir the connected water is what the player is standing in.
• One open item for Combat, not a request. DES104 §3.1 gives the Lock Flight a floater carried by flowing water, with attraction yielding to flow. The spill channel here assumes that rule, because a race that moves bodies is what makes opening a race a choice. CMB101's roster does not contain a flow-carried role. Either the floater is Combat's to adopt, or this district's spill channel moves nothing and §3's third option loses its sweetener — the decision still stands, it is just less generous. Combat and the lead should settle which; this page does not need it resolved to work.

9. Asset reuse and gaps

Reused: races, weirs, water planes and wet/dry tinting, drums and shafts, cable, lamps, beacons, a three-position panel, hand-worked gates, boards and tallies, walkway and gallery props, dock props, the humanoid mass.

Genuine gaps, marked and not filled. No free asset has been located, checked or licensed for any of these, and nothing here authorises creating one (Brief D009).

• A large reservoir and dam exterior. The campaign's biggest single art ask, and the only district that cannot be dressed out of the pumping district's kit.
• The governor as an oversized multi-position machine with per-district state readable at a glance. It is a panel, but it is the panel the whole campaign has been building toward, and dressing it as an ordinary one would undersell the ending.
• Conditional, and attached to a decision the owner has not yet made: one human presence, if Answer B is chosen (§7).

A cheaper alternative, recorded now. If the reservoir exterior is out of reach, the district can be staged entirely inside the works — gallery, race heads and a weir seen through an opening — which keeps every decision in §3 and §4 and loses the one view the finale would most want. I would fight for the view and I would not fight for it at the cost of the district.

10. Open questions and dependencies

• REV104-1 — RESOLVED. The shared contract r3 now states it as a rule: the drum makes the moment, the trunk permits it; Stop stops the drum, a dark bank position withholds the trunk, either alone stops announced surges. Stop and Keep in §4 rest on ratified text rather than on an assumption, which was the single ruling this page most needed.
• REV104-4 — RESOLVED, and it landed in this district. The contract's fixed-power source is the head-works' store of harvested charge, distributed from a switch-house that is now part of this district's ground (§2). D024 adopts Answer A provisionally, so §7's coupling between the answer and the power source is settled rather than open — and §7's note about what Answer B would cost stands, because D024 is marked provisional.
• World (WLD103). §6's redundant clue form; the tally room's contents; the campaign's answer. All proposals in their domain, and this district is built to survive their replacement.
• Lead (DES104). Whether this page contradicts anything in the campaign page; if so, that page wins until agreed otherwise. Also §2's race route, which adds a second approach to the boat range in DES104 §5.
• COL101. Keep makes the governor a standing colony setting, which is a persistent-progression object in Colony's domain rather than mine. If Colony would rather it were not, Keep can remain a one-time setting with no return trips, and the district still works.
• CMB101. The Grounder placement in §8, and the floater question in §8's last bullet.
• Withdrawn, and recorded as withdrawn. r1 kept a third governor position, Slow, and flagged it as the one I would cut first. PMR004 cut it for a better reason than mine — it was reproducible by Keep — and I accept that; the reasoning is in §4 and the r1 wording is in page history. What I got right was the instinct; what I got wrong was keeping a position I could not defend.
• Unresolved by me, honestly. Whether Keep asks too much of a finale — it is the only outcome that is several interactions rather than one, in the campaign's most exposed room, and a player who wanted a clean ending may experience it as homework rather than as power. I do not know, and it is the first thing I would want watched if a play phase is ever authorised.