The **Echo Relay** is a proposed late, one-cell electrical module that turns previously tuned wet landmarks into repeated origins for one coordinated Coil-and-Arc discharge. It is the new component in the proposed **Choir Cascade**. It does not strengthen every attack, power arbitrary scenery or replace the early Cutter, Coil or Arc; it rewards remembering where conductive landmarks are, bringing the old parts together and surrendering most or all carrying capacity for a prepared crowd-clearing event.

**Player action and trigger.** At a shelter the player fits the six-cell chassis and chooses the two links. In the field, after tuning the authored bells or another explicitly Relay-compatible wet landmark network, the player selects Echo Relay. The preview requires both linked batteries full, a valid connected wet footprint, and at least one tuned landmark currently visible. Confirming spends both ten-charge banks at once. A dry or incomplete network, a partial bank or an incompatible landmark refuses without cost. The Relay then becomes **spent** until the next shelter, even if the batteries are refilled; this prevents immediate loops from the cleared crowd's normal motes without inventing a no-yield enemy exception.

**Visible information.** Before confirmation, draw the conductive footprint, number each eligible landmark, show the bodies each origin currently claims, mark duplicates as claimed by the nearest origin, and state `20 charge / Relay spent until shelter`. Use lines, symbols and counts in addition to colour. When the network is broken, show the first dry gap or untuned landmark. During the effect, Coil power and Relay-origin arcs need distinct cues; this page claims no art asset or verified readability.

**Resource and opportunity cost.** The base build spends twenty charge, consumes six cells and leaves only two for cargo or safety. It has no Insulation, Kit, Beacon or alternative primary unless the player gives up part of the cascade. Carrying two ordinary bundles retains a hauling payoff but risks leakage if packed against a charged bank. Firing early may clear only a few bodies and still spends both banks plus the Relay's one activation.

**Restrictions and counterplay.** Dry ground breaks the environmental repetition. Untuned metal and ordinary lamps are not origins. Crust, isolated armoured enemies and bodies beyond the wet landmark footprint survive; a later wave arrives after the Relay is spent. The effect does not emit signal, destroy clues, power arbitrary devices, bypass grounded runs, retrigger itself or let Arc hits become new landmark origins. Ordinary eligible kills keep the existing once-per-organism mote rule and still require physical collection before fade. The spent state, manual collection and surviving second wave prevent the first clear from being an automatic repeat.

Bring the legal base rack and reserve the last two cells for finds. Tune the wet landmarks, let the crowd fill their footprint, preview the distinct Arc claims and fire. The player learns that the old Coil does more than hold bodies: in the Relay network its short world-power pulse decides where the retained Arc begins. The payoff is a broad but capped clear. The weakness is preparation dependence; a Crust or dry flank can leave a dangerous survivor between the player and the dropped motes. The reason to keep the early parts is structural: removing Coil removes the wet pulse, removing Arc removes damage, and removing either battery makes the trigger illegal.

- **Colony:** place Relay issue/recipe access within the growing Hearth without making it a strict upgrade or granting it free alongside every service.