The astronaut enters a hospital transfer concourse because a window above it shows a constellation that was not there before the last death. A rail-mounted lamp can scan it, but the carriage is at the wrong end. Its station supply is visibly live. Releasing its mechanical brake starts the carriage moving at walking pace. The player can run ahead, fall behind or circle it. Bodies slow the carriage until its rail is cleared, then it continues.

The machinery wakes the concourse. About forty shambling patients spill from two wards across the central lane. A dozen faster creatures descend marked maintenance stairs in flanking groups; more silhouettes press behind ward glass. The player's later-game **Storm Choir** has automatic Projector fire, impact-powered arcs and a charge store, but begins this trip without its temporary transformations. Its short electrical chains help without dominating the space.

At the first junction the crowd thickens. The player stays near the packed centre so each arc can continue through adjacent bodies, then cuts aside when the fast group arrives. The ward release is finite and visibly runs out. Clearing its committed crowd earns a choice under the proposed stage reward rule. In the paused journal the player chooses **Echoing Arc**: each accepted Arc action gains two further finite branch routes at a heat cost. It resumes the same danger when the journal closes.

At the next junction, the carriage trips a second marked ward release. Resolving it offers **Thunderhead**, adding a manual full-store burst to the same rig. Ordinary Projector impacts charge the store. Each Arc discharge spends its supplied charge; the extra jumps add heat. These two releases prepare the build for the final optional scan. At either junction the player can stop the carriage and leave by the walking route.

The final ward doors open ahead. Roughly one hundred enemies fill the concourse, with more flowing from announced sources. A tide closes from behind while fast groups cross the carriage's path. The player risks the dense middle, finishes charging and presses Thunderhead. Stored charge discharges through three chain heads and one penetrating pressure lance, then charging restores automatically. **The intended climax** is blue-white branching light breaking roughly forty well-packed ordinary bodies while the lance cuts a traversable slot. Survivors, flankers and resistant bodies still move. The carriage surges through because the player chose the dense line and the release moment, not because the special deleted the room.

An unready player sees the crest turn against them. Flankers draw arcs away from the tide, bodies stall the carriage, and a heavy creature narrows the exit while hits strip condition. The choice is legible: spend Thunderhead early and face the main mass empty; hold the centre long enough to charge, risking death; or abandon the scan and flee, spending oxygen and position. The walking route remains usable without an overclock. Death changes the next route, but everything physical still carried returns aboard. The horde has teeth without deleting the loadout.

At the far window the final source gates close, stopping further arrivals. The player clears the creatures already beside the carriage or leaves them separated behind a pedestrian bulkhead before investigating. The “constellation” is a live map of rooms that are currently far apart. Its last line unfolds an overhead bridge toward the matching point—a route the player can walk now. An earlier recorded mark suggests another scan track may reveal a second bridge elsewhere. The player can push onto the new span with reduced oxygen or bring that recorded connection home and plan the next trip. Combat delivered access; knowledge points to a specific next action.

A **horde** surrounds routes, feeds a build continuously and changes the whole screen when it breaks. A developed encounter in a broad ward, dock or cargo artery might show 80–150 enemies together and pass several hundred through its full crest. Narrow corridors can show less while a continuous river arrives through doors, lifts and ducts. Hospitals, transit systems and sealed infested volumes are believable **source areas**: places holding bodies that can physically enter a connected route when disturbed.

4. **Break.** The player clears the finite release or completes a physical seal at its source. Sealing stops arrivals; creatures already inside still need clearing or safe separation before investigation. Music, enemy flow and the room's silhouette release together. The resulting lull belongs to inspection, salvage, route choice and discovery.

Killing faster than a source can feed buys room to move while it is still active. Outrunning the crowd buys escape. A resolved release stays spent in the current station arrangement; returning to the same source does not make it pay again. Further releases need their own announced physical source. A powerful build is allowed to erase an ordinary crest and enjoy the silence it bought. [Fighting the Horde](/Hold%20The%20Flood/Combat%20Rules) explains sources, stage rewards and the difference between a cleared lane and a quiet room.

Combat stays regular because exploration crosses inhabited volumes and because movement, machinery and fighting can wake adjacent source areas. Quiet rooms and earned breaks remain essential; without them, clues become visual noise and a climax has no shape.

Temporary transformations create a survivorslike rise from “barely holds a lane” to “breaks the crest it prepared.” Echoing Arc grows finite chain routes, Rebound Disc makes architecture part of a shot, Inward Draft makes running shape the crowd, and the three final transformations turn stored charge into a climax. The chosen behaviour changes automatically. The pleasure should come from deciding what this expedition's machine will become, then seeing that decision reshape the next crowd.

**How often growth arrives is still an owner choice.** The current proposal used by the moving scan awards one choice for clearing a finite, announced release or sealing its access after it begins, including an early victory. Closing the source beforehand instead buys safety and access without an upgrade choice. The alternative is regular growth from defeated enemies with larger milestone transformations. Neither should reward delaying a harmless last enemy. [Build Rules](/Hold%20The%20Flood/Build%20Rules) explains temporary effects and growth choices; [Fighting the Horde](/Hold%20The%20Flood/Combat%20Rules) explains how a sourced horde is resolved.

The owner selected resetting temporary combat upgrades on every return home. Each expedition gets a fresh rise in power; delivering a survivor, following a new clue and preparing another combination give that rise a purpose beyond its last spectacular clear. A living return must leave a useful route to that next rise, rather than make death the efficient way to find fresh crowds.

**What it does.** Automatic Projector impacts feed electrical chains and bank charge. The player moves toward dense, mutually visible knots so each finite route can continue, then manually discharges the full store when the crowd is fullest. Ordinary charging restores itself after the burst.

**Connection in plain language.** Threat Sensor starts Pulse Projector. Physical impacts supply Impact Dynamo; Fork Relay divides its charge between Arc Emitter and Capacitor. Echoing Arc adds two branch routes. Thunderhead switches the full store through Fork to Arc and Projector for one manual burst. These six parts use seven carrying and mounted spaces on a later rig; one normal oxygen canister leaves one of the proposed ten carrying spaces for salvage.

**Ordered transformation.** The base chain first rewards a compact lane. Echoing Arc then turns one chain into three finite routes. Thunderhead finally spends a full store on three chain heads plus one pressure lance, enough to break roughly forty well-aligned ordinary bodies while leaving the rest of a large horde active. The exact hop, cover, heat, supply and coverage contract lives in [Mechanical Interfaces](/Hold%20The%20Flood/Mechanical%20Interfaces%20And%20Opening%20Quantities). No step assumes an XP threshold, pickup frequency or particular reward cadence.

**Weakness, choice and bad feel.** Insulated bodies, hard cover or wide spacing stop routes. Storage and Arc consume space that could support defence, oxygen or focused force, and the burst adds a high heat pulse. This rig has no Barrier. The player chooses whether to cross toward a dense connected knot or spend early on a weaker line. It may feel bad when one insulated body at the front consumes the spectacular setup and the remaining branches cannot reach the crowd the player thought they had framed; the preview must expose that break before commitment.

**What it does.** Rebound Disc automatically launches a glowing physical disc on a committed direction. Fragment Wake turns its normal terminal end into one forward fragment fan. Successive finite flights overlap between hard surfaces while the player runs for new angles and manually shoves eligible bodies or loose cover into the next path.

**Connection in plain language.** Threat Sensor starts Pulse Projector. Its first eligible physical impact supplies Impact Dynamo, which charges Capacitor. Manual Trigger operates Vector Nozzle for the shove. Rebound Disc, Fragment Wake and Foundry Drop change Projector temporarily. These six parts use seven carrying and seven mounted spaces. Nozzle moves bodies and loose objects; it never steers a disc. Each original launch gives Dynamo at most one contribution, however many descendants hit.

**Ordered transformation.** The base ordinary shot and manual shove first hold one corridor. Rebound Disc then rewards one readable bank. Fragment Wake adds a terminating fan and makes each accepted automatic shot threaten a broad corridor. Foundry Drop finally turns a full store into one manual master disc with a longer but finite path and larger fan, capable of breaking roughly half of a tightly framed 80–100-body crest. Its flight never homes, and the automatic launch mode restores after dispatch. Exact travel, rebound, body, fragment, supply and heat limits are in [Mechanical Interfaces](/Hold%20The%20Flood/Mechanical%20Interfaces%20And%20Opening%20Quantities). The ordering does not select how often offers appear.

**Weakness, choice and bad feel.** Open atriums, soft partitions and absorbing enemies deny useful rebounds. Bringing Manual and Nozzle spends the space Storm Choir uses for Fork and Arc; this rig also lacks a Barrier. The player chooses a running angle and whether to spend Nozzle now to improve a later disc or save it for escape. It may feel bad when the disc meets an absorber before its terminal wall and produces no fragment fan; the path preview and absorber response must make that risk legible rather than look like missing effects.

**What it should do.** The astronaut gathers a dangerous wake of enemies while running, then burns through the compressed mass with a chosen thermal burst. Its pleasure is the moment pursuit becomes ammunition for the player's plan: keep the knot together for a spectacular release, or fire early to escape it.