Source: [Design Document r14 / ec1b6c](/Hold%20The%20Flood/Design%20Document?revision=ec1b6c), §§4–6 and 8; [World r20 / 7699de](/Hold%20The%20Flood/World%20And%20Mystery?revision=7699de), W1 and price of the panel. [Design Index](/Hold%20The%20Flood/Design%20Index) · [Expansion Brief](/Hold%20The%20Flood/Expansion%20Brief) · [Glossary](/Hold%20The%20Flood/Glossary).

**Player action and trigger.** Select Coil and discharge while the player stands in the connected water to be energized. Require a full linked battery; a dry target or insufficient charge refuses the action without spending. The player positions and times the discharge; there is no automatic firing whenever a battery fills.

**Effect and target.** Spend all ten units from that battery. Inject current into connected water for a brief interval; propose eight seconds, matching the source scene's stun duration. Every connected powered device works during that interval. Eligible enemies in the water are stunned under Combat's grammar. Fresh organisms shed under the shared once-per-organism rule: source proposal five units per ten organisms; ordinary kills after shedding yield nothing. Refresh/overlap and exact boundary targeting need Combat's disposition before integration.

**Space and resources.** Two adjacent rack cells, rotated at shelter; a separate battery costs one more. Insulation adds a fourth if the player wants protection from the water they energize. A reserve bank adds a fifth but does not link in parallel; shelter rewiring remains necessary.

**Visible information.** Charge/full-action state; the connected water and observed devices highlighted before discharge; steady powered beacons, no signal pulse; stun/recovery and spent-yield markings that do not depend only on tint. Showing the intended stun interval is a design requirement, not a claim that timing has been validated.

**Restrictions and price.** No dry-ground mass stun, no signal generation, no intake change, no repeated charge from a spent crowd. Uninsulated users suffer the existing water hazard. A valve or cable may extend power to an unwanted beacon; do not secretly restrict it to the selected door. Partial charge never produces a weaker hidden discharge. Charged water can be abandoned, but money spent is not refunded.

**Combinations and reasons to retain it.** Coil + Insulation makes gathering inside a hot channel possible; second Battery saves more of a fresh harvest; Arc spends a separate bank after the crowd recovers. Cable Reel can extend its temporary power to a reachable terminal. The coil remains the catalogue's independent temporary power source and wet mass-control action; no later item upgrades those jobs away.

**Acquisition.** First visible machinery cache reachable with the free panel/valve route. Inspect to learn the recipe, pick up into a legal two-cell space, fit/link at shelter. Later machinery caches and workshop choice use the [acquisition contract](/Hold%20The%20Flood/Equipment/Build%20Paths#acquisition-and-advancement). It starts uncharged; early trigger opportunities must include reachable charge, not assume one Siphon fills an empty battery.

Illustration: with panel on Causeway and its crowd holding at nearer B1, shut the junction valve and discharge in the isolated junction pool. The gate opens briefly; its ordinary indicator is not a lure. The B1 crowd stays. This preserves World's knowledge-based route: opening the valve and lighting the yard is the free alternative, with a different water/crowd cost.

Counterplay using existing enemies: a crowd spreads across dry ground or has already shed. The coil can neither harvest that dry crowd nor fund a second wet stun from spent organisms. Use the cutter to thin a safe edge, attract a fresh crowd into water, or leave. “Harvest forty and refill both banks” elsewhere is conditional on fresh targets and actually reaching the motes, never a guaranteed result.

Retain two-cell size, full-bank spend, water propagation, shelter links and once-only yield. Proposed clarification: explicit failed-trigger behaviour and an eight-second power interval tied to the illustrative stun interval; Lead/Combat may separate those durations if they state and display both. [Inventory and Charge](/Hold%20The%20Flood/Mechanics/Inventory%20And%20Charge) records the transfer request; no source rule has been overwritten.