Bourdon

At a glance: Scourge subterranean Choir-repeater · Bone Titan Host rooted into descent rock · severs the deep-to-surface Choir column when destroyed · appears in Scourge-Survivors / Deadlane / The-Listeners.

A subterranean Choir-repeater — the fourth named relay class after the rooted Chorister, the mobile Cantor, and the orbital Descant, and the one that carries the Choir (CANON §5–6) up the rock. A Chorister extends the signal’s radius across a surface breach; a Cantor extends its range of motion along a lane; a Descant extends it vertically upward, up the gravity well to orbit. A Bourdon extends it vertically downward — it bridges the deep source-nest to the surface front through solid stone. It is a Bone Titan Host grown into the throat-walls of the descent, a vast buried frame droning so low you feel it in the rock before you hear it.

The signal is made at the bottom — the Choir Node in Perdition, the densest repeater-heart on the war-map — but the Choir’s radius can no more cross a mile of stone than it can cross vacuum. The connection has to be carried up the throat in a chain: the deep nest, then Bourdons rooted up the shaft through the Maw and the dark above it, then surface Choristers feeding Cantors out the lanes and Descants up to the sky. While a Bourdon sings, the surface horde and the deep nest share one set of eyes through the ground: a wave on the lanes attacks already knowing what’s climbing the shaft beneath it, and the deep sees the surface fight pressing down. Sever a Bourdon and you don’t blind the source — it is far too dense to sever, the way Perdition is — you cut the column: the stretch of descent above the kill loses the deep nest’s sight, and that segment falls feral, climbing into a war it can no longer read.

Behaviour

• Deep-rooted, immobile. Roots into the throat-wall of a descent shaft — fused rib-frame and horn-plate sunk into living stone — and never relocates; like the Chorister it is planted, just planted in the deep dark. It holds its station in the rock the way a Descant holds high station in the sky: depth is the whole point, and it never willingly climbs.
• While it lives, the Scourge above and below it on the shaft is connected through the rock: units on the surface and in the throat flank, focus-fire, and pre-empt movement as one mind (CANON §5), a pincer that reads the descent top to bottom. The bubble is vertical and narrow — it reaches up and down the column of stone, not out across it.
• Barely attacks. Its only direct threat is a slow subsonic resonance toll that staggers attackers and briefly scrambles their footing and targeting in the dark — a tremor you feel through the span before the body even comes into the light. It is defended by the horde climbing past it.
• On death the column is severed. Every connected Scourge on that stretch of the descent drops to feral (CANON §6): the climbers above lose the deep nest’s sight, flanking collapses, the pincer comes apart. Smaller than severing a whole surface front — you blind a segment of shaft, not a breach — but it cracks the descent open one link at a time.
• Defended fanatically, the way the Scourge guards any relay — it spends bodies up the walls it would never otherwise burn to keep one Bourdon tolling, because losing one blinds the descent from below and hands a Purger a window in the worst place to need one.
• Killing a Bourdon does not kill the Scourge (CANON §2). The Choir persists; the deep nest grows a new Bourdon into the next bend of the shaft and the column re-roots in the rock overhead.

Gameplay Read

• A deep priority target and gate — the subterranean counterpart to the surface Chorister objective, met on the way down rather than across a lane. The skill check is reaching it: it sits in the throat behind the climbing swarm, and the correct play is to fight down through the coordinated horde to the relay, then survive the feral remnant on a span over the dark.
• Telegraph: a slow toxic-green resonance toll pulses up the shaft-wall like a struck bell, and the climbers above and below flinch and snap into sync with each beat — the same “these are connected” grammar as the Chorister, Cantor, and Descant, staged on the vertical-down axis. You feel the toll in the rock — screen-shake and a low sub-bass — before you see the body.
• The instant it dies, the stretch of descent above it visibly comes apart: climbers lose their footing-sync, the pincer slackens, the swarm on the walls stops leading you. The severance reads at a glance, no UI needed — the deep goes quiet under your boots.
• Frames the descent’s connective payoff: breaking a Bourdon in the shaft is why a contested lane far overhead suddenly stops seeing a Warden coming. The surface front and the deep nest are one Choir, climbing the same rock — and this is the node that proves it from below, exactly as a Descant proves it from above.

Visual Motifs

• A vast rooted relay grown into living rock — a Bone Titan Host of fused rib-cage, horn-plate, and massive buried limb-frames sunk into the throat-wall and overwritten by parasite tissue; clearly something planted in stone, half-swallowed by the shaft, not something that walks.
• Clustered resonator membranes and faceless droning throat-sacs packed deep in its frame — the Chorister’s singing organs re-grown for the low end — open, wet, swollen, pulsing slow and heavy in time with the toll.
• Toxic-green Choir nodes laddered up the buried spine, brightest at the crown breaking out of the rock-face; the up-facing emitter, the obvious “where do I shoot” answer in the dark.
• Tendrils and root-knots driving down and out into the stone — the column you can see, threading away into the rock toward the deep nest below rather than reaching across open ground.
• Rock-face overwritten by host-bone and parasite tissue, rupture seams bleeding green into the stone; the throat-wall of the Maw made flesh around it, warm and ribbed.

Sprite Brief

• Views: front, side, back — readable in Scourge-Survivors’s close, dark FPS framing, lit mainly by its own crown-glow and muzzle flash.
• Silhouette must read as half-buried, rooted-in-rock, and immense — instantly distinct from the tall surface-mast Chorister, the low scuttling Cantor, and the wreckage-rooted Descant.
• The crown node breaking out of the rock-face is the focal point: brightest up-facing Choir emitter, visible behind the climbing screen.
• Pulse state: a tolling variant with crown and embedded throat-sacs flared blood-hot-to-toxic and the rock-face around it visibly trembling.
• Sever state: a guttering variant — crown going dark, membranes slack, root-knots tearing loose from the stone — so the kill reads clearly in low light.

Prompt Seed

Scourge subterranean Choir-repeater, bone titan host grown into living rock, vast fused rib-cage and horn-plate and buried limb-frames sunk into a cave throat-wall and overwritten by parasite tissue, clustered wet faceless droning throat-sacs packed deep in the frame, toxic-green Choir nodes laddered up the buried spine brightest at the crown breaking out of the rock-face, tendrils and root-knots driving down into the stone toward the deep nest below, rupture seams bleeding green into the rock, tolling a slow subsonic resonance pulse, warm ribbed throat-walls, blood and rust and gunmetal, DOOM-like heavy shadows, no neon.

Appears In

• Scourge-Survivors — the relay rooted in the throat-shaft on the descent past the Maw toward Perdition: while it tolls, the climbing horde fights as a coordinated pincer that reads the shaft top to bottom; sever it and that stretch of descent goes feral, buying the lone Pyre Purger the window to push deeper. The deep counterpart to a surface Chorister objective.
• Deadlane — felt, not fought: while a Bourdon tolls in the rock beneath a held lane, the surface wave arrives pre-aimed and coordinated with whatever is undermining the wall from below; a Warden who breaches down and breaks it cuts the pincer and the lane stops seeing the player coming. The downward mirror of a Descant’s overhead handoff.
• The-Listeners — the deepest ear on the Choir, and nearly the hardest to reach. A Bourdon taken intact would be the heresy’s view of the signal closest to the source (CANON §8), down by the Choir Node itself — coveted, almost never won, because the descent it sits in is the one no one walks out of.