diff --git a/CLAUDE.md b/CLAUDE.md
index 802ca14..b901d84 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -82,9 +82,16 @@ Date.now/Math.random inside sim).
    fire within 3 tiles then is spent). Flaky used cards (p106/mtt_s80/
    radish580) die under load. Ad-spend slider (log-diminishing hype) +
    email Spam Blast (instant views, 60s cooldown, 15% blacklist risk).
-→ M8 backlog: ACTIVE scraping minigame, subscribers/SaaS churn revenue,
-   warehouse room (tier 3), Conveyor belt visual, per-carrier PSU,
-   liquid/immersion cooling for racks (fires make it necessary).
+✅ M8: warehouse tier (20x20, 8kW, MOVES ladder has from-fields now);
+   immersion tank (fire-immune carrier, card heat x0.15, 8 rack-class
+   slots) + CRAC unit + AIO socket; SaaS subscribers — signups from live
+   view rate (SAAS.CONV), churn on latency (serve demand > inference
+   share), collapse, and breaker trips (-15% instant); serving eats
+   inference tokens BEFORE the video pipeline. SUBS stat in HUD with
+   latency warning.
+→ M9 backlog: ACTIVE scraping minigame, Conveyor belt visual,
+   per-carrier PSU, Tier 4 campus + strategic map layer, win/lose
+   states, sound design pass, Steam packaging decision.
 Design pillars (John-approved framing): Throughput, Allocation, Attention,
 Capital, Expansion. Macro layer (Tier 4-5) = strategic map, NOT city-builder.
 Cut until earned: Tiers 3–5, immersion cooling, offshore ships, lobbying.
diff --git a/public/assets/gen/crac_unit.png b/public/assets/gen/crac_unit.png
new file mode 100644
index 0000000..5be8350
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diff --git a/public/assets/gen/crac_unit_cut.png b/public/assets/gen/crac_unit_cut.png
new file mode 100644
index 0000000..befad2d
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diff --git a/public/assets/gen/immersion_tank.png b/public/assets/gen/immersion_tank.png
new file mode 100644
index 0000000..a1b0830
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diff --git a/public/assets/gen/immersion_tank_cut.png b/public/assets/gen/immersion_tank_cut.png
new file mode 100644
index 0000000..9b549f3
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diff --git a/public/assets/gen/warehouse.png b/public/assets/gen/warehouse.png
new file mode 100644
index 0000000..55602d8
Binary files /dev/null and b/public/assets/gen/warehouse.png differ
diff --git a/src/sim/balance.ts b/src/sim/balance.ts
index 9305341..5b2ee99 100644
--- a/src/sim/balance.ts
+++ b/src/sim/balance.ts
@@ -59,4 +59,15 @@ export const BAL = {
     { name: "v3", mult: 12, tokens: 250_000, vramGB: 512, checkpointGB: 3_000 },
   ],
   VRAM_STARVE_FLOOR: 0.25, // token multiplier floor when VRAM-starved
+
+  // SaaS: subscribers funnel in from views, churn out on latency/downtime.
+  SAAS: {
+    CONV: 0.003, // signups per view
+    CHURN_S: 0.00033, // ~2%/min baseline
+    SUB_REV_S: 0.004, // $/s per subscriber
+    TOK_PER_SUB: 0.02, // tok/s each subscriber's requests consume (from slop share)
+    LATENCY_CHURN_MULT: 3, // when serve demand exceeds inference supply
+    COLLAPSE_CHURN_MULT: 3, // gibberish product
+    TRIP_HIT: 0.15, // subscribers lost instantly on a breaker trip
+  },
 };
diff --git a/src/sim/catalog.ts b/src/sim/catalog.ts
index a1f4940..4b8cd40 100644
--- a/src/sim/catalog.ts
+++ b/src/sim/catalog.ts
@@ -17,6 +17,8 @@ export interface DeviceDef {
   ports?: number; // wired-device capacity for router/switch-class (default 4)
   storageGB?: number; // checkpoint capacity
   circuitBonus?: number; // extra breaker watts (electrical infrastructure)
+  fireImmune?: boolean; // cannot thermally run away (immersion)
+  cardHeatMult?: number; // carrier-level multiplier on installed-card heat
   burnRate?: number; // $/s consumed while running (cash furnace)
   hypeMult?: number; // bonus view multiplier while burning (stacks multiplicatively)
   wallOnly?: boolean;
@@ -87,6 +89,13 @@ export const CATALOG: DeviceDef[] = [
     wattsIdle: 150, wattsLoad: 250, tokRate: 0, heatOut: 2, gpuSlots: 8, rackClass: true,
     footprint: { w: 2, h: 2 }, sprite: "server_rack_mini", unlockAt: 900,
   },
+  {
+    id: "immersion_tank", name: "Immersion Tank", cat: "compute", cost: 4000,
+    desc: "Eight slots under mineral oil. 85% less heat, cannot catch fire. Smells like chips.",
+    wattsIdle: 250, wattsLoad: 400, tokRate: 0, heatOut: 1, gpuSlots: 8, rackClass: true,
+    fireImmune: true, cardHeatMult: 0.15,
+    footprint: { w: 2, h: 2 }, sprite: "immersion_tank", unlockAt: 5000,
+  },
   // --- network ---
   {
     id: "router", name: "Wi-Fi Router", cat: "network", cost: 40,
@@ -166,6 +175,13 @@ export const CATALOG: DeviceDef[] = [
     coolRate: 14, wallOnly: true, footprint: { w: 1, h: 1 },
     sprite: "window_ac", unlockAt: 150,
   },
+  {
+    id: "crac_unit", name: "CRAC Unit", cat: "cooling", cost: 1500,
+    desc: "Precision air for people whose 'computer room' is real now.",
+    wattsIdle: 200, wattsLoad: 1600, tokRate: 0, heatOut: 0,
+    coolRate: 30, footprint: { w: 1, h: 1 },
+    sprite: "crac_unit", unlockAt: 2500,
+  },
   // --- misc ---
   {
     id: "desk", name: "Desk", cat: "misc", cost: 15,
diff --git a/src/sim/research.ts b/src/sim/research.ts
index e8cfe47..0d4d31e 100644
--- a/src/sim/research.ts
+++ b/src/sim/research.ts
@@ -212,6 +212,7 @@ export const SOCKETS: SocketUpgrade[] = [
   { id: "extra_fan", name: "Extra Fans", cost: 80, desc: "Heat -25%", heatMult: 0.75 },
   { id: "undervolt", name: "Undervolt", cost: 150, desc: "Watts -15%, tokens -5%", wattsMult: 0.85, tokMult: 0.95 },
   { id: "risers", name: "Riser Cards", cost: 250, desc: "Tokens +15%, heat +15%", tokMult: 1.15, heatMult: 1.15 },
+  { id: "aio_loop", name: "AIO Liquid Loop", cost: 400, desc: "Heat -50%", heatMult: 0.5 },
 ];
 export const SOCKET_SLOTS = 2;
 
diff --git a/src/sim/rooms.ts b/src/sim/rooms.ts
index 2752053..f5d42f8 100644
--- a/src/sim/rooms.ts
+++ b/src/sim/rooms.ts
@@ -25,8 +25,14 @@ export const ROOMS: Record<string, RoomDef> = {
     w: 14, h: 14, tileW: 58.5, tileH: 29.5, origin: { x: 510, y: 330 },
     imgW: 1024, imgH: 768, breakerBase: 2400,
   },
+  warehouse: {
+    id: "warehouse", name: "The Warehouse", image: "/assets/gen/warehouse.png",
+    w: 20, h: 20, tileW: 41, tileH: 20.5, origin: { x: 510, y: 330 },
+    imgW: 1024, imgH: 768, breakerBase: 8000,
+  },
 };
 
-export const MOVES: { to: string; cost: number; unlockAt: number; blurb: string }[] = [
-  { to: "garage", cost: 3000, unlockAt: 2500, blurb: "Mom wants her bedroom back. 14x14 of concrete, 2.4kW service." },
+export const MOVES: { from: string; to: string; cost: number; unlockAt: number; blurb: string }[] = [
+  { from: "bedroom", to: "garage", cost: 3000, unlockAt: 2500, blurb: "Mom wants her bedroom back. 14x14 of concrete, 2.4kW service." },
+  { from: "garage", to: "warehouse", cost: 25000, unlockAt: 15000, blurb: "Industrial unit, zoned 'flexible'. 20x20 tiles, 8kW three-phase." },
 ];
diff --git a/src/sim/sim.ts b/src/sim/sim.ts
index ff54a51..7f11e08 100644
--- a/src/sim/sim.ts
+++ b/src/sim/sim.ts
@@ -187,6 +187,7 @@ export function moveRoom(s: SimState, to: string): string | null {
   const mv = MOVES.find((m) => m.to === to);
   if (!mv || !ROOMS[to]) return "nowhere to move";
   if (s.room === to) return "you already live here";
+  if (mv.from !== s.room) return `that move starts from the ${ROOMS[mv.from].name}`;
   if (s.earnedTotal < mv.unlockAt) return `earn $${mv.unlockAt} total first`;
   if (s.cash < mv.cost) return "can't afford the bond";
   s.cash -= mv.cost;
@@ -503,6 +504,10 @@ export function step(s: SimState) {
         const loss = Math.round(BAL.CHECKPOINT_LOSS * 100);
         s.trainTokens *= 1 - BAL.CHECKPOINT_LOSS;
         pushEvent(s, `⚡ BREAKER TRIPPED — checkpoint corrupted (-${loss}% training)`, "bad");
+        if (s.subs >= 1) {
+          s.subs *= 1 - BAL.SAAS.TRIP_HIT;
+          pushEvent(s, `📱 Outage! ${Math.round(BAL.SAAS.TRIP_HIT * 100)}% of subscribers rage-quit`, "bad");
+        }
       }
     }
   } else if (watts <= limit) {
@@ -523,9 +528,10 @@ export function step(s: SimState) {
     const def = DEF[d.defId];
     if (!d.powered) continue;
     // packed cards choke airflow — heat rises superlinearly, and throttling
-    // does NOT cool a crammed chassis (that's how runaways happen)
+    // does NOT cool a crammed chassis (that's how runaways happen).
+    // Immersion tanks dampen card heat instead (cardHeatMult).
     const packMult = 1 + 0.15 * Math.max(0, d.gpus.length - 1);
-    const cardHeat = cardStats(d).heat * packMult;
+    const cardHeat = cardStats(d).heat * packMult * (def.cardHeatMult ?? 1);
     if (def.heatOut || cardHeat)
       heat[idx(d.x, d.y)] += (def.heatOut + cardHeat) * d.util * dt * 2.2 *
         (isCompute(def) ? mods.heatMult * deviceMods(d.upgrades).heat : 1);
@@ -566,7 +572,7 @@ export function step(s: SimState) {
       const over = d.temp - BAL.THROTTLE_C;
       d.perf = over <= 0 ? 1 : Math.max(BAL.THROTTLE_FLOOR, 1 - over / 30);
       // thermal runaway: sustained >95°C under load ignites the hardware
-      if (d.temp > 95 && d.util > 0.5) {
+      if (d.temp > 95 && d.util > 0.5 && !DEF[d.defId].fireImmune) {
         d.hotSince ??= s.t;
         if (s.t - d.hotSince > 10) igniteDevice(s, d);
       } else {
@@ -655,9 +661,12 @@ export function step(s: SimState) {
     pushEvent(s, `🤖 Platforms updated their spam filters (wariness ${Math.round(stages[s.adaptStage - 1] * 100)}%)`, "bad");
   }
 
+  // SaaS serving eats inference first — paying customers get the tokens
+  const serveNeed = s.subs * BAL.SAAS.TOK_PER_SUB * dt;
+  const saasLatency = s.subs > 1 && serveNeed > tokInf;
   // slop videos — richer modalities cost more tokens per video but earn far more
   const videoCost = BAL.VIDEO_COST_TOK * mods.videoCostMult;
-  s.tokenBank += tokInf;
+  s.tokenBank += Math.max(0, tokInf - serveNeed);
   while (s.tokenBank >= videoCost) {
     s.tokenBank -= videoCost;
     const viralChance = BAL.VIRAL_CHANCE + mods.viralChanceAdd;
@@ -791,6 +800,7 @@ export function step(s: SimState) {
 
   const adaptMult = (1 - s.platformAdapt * BAL.ADAPT_MAX_PENALTY) * hype * adHype * viewFx *
     mods.viewsPerVideoMult * mods.conveyorHype * (hostingOwnMax ? 1.1 : 1);
+  let liveViewRate = 0;
   for (const v of s.videos) {
     if (v.dead) continue;
     const age = s.t - v.born;
@@ -799,9 +809,28 @@ export function step(s: SimState) {
       Math.exp(-age / (BAL.VIDEO_LIFETIME_S / 3));
     v.views += v.rate * dt;
     s.totalViews += v.rate * dt;
+    liveViewRate += v.rate;
     income += (v.rate * dt * BAL.CPM) / 1000;
   }
 
+  // --- SaaS: the "Instant Girlfriend App" wrapper business ---
+  let subsNet = 0;
+  if (s.shippedGrades.length > 0) {
+    const signups = liveViewRate * BAL.SAAS.CONV * dt;
+    let churn = BAL.SAAS.CHURN_S;
+    if (saasLatency) churn *= BAL.SAAS.LATENCY_CHURN_MULT;
+    if (s.collapsed) churn *= BAL.SAAS.COLLAPSE_CHURN_MULT;
+    const before = s.subs;
+    s.subs = Math.max(0, s.subs + signups - s.subs * churn * dt);
+    subsNet = (s.subs - before) / dt;
+    income += s.subs * BAL.SAAS.SUB_REV_S * dt;
+    const stages = [100, 1_000, 10_000, 100_000];
+    while (s.subStage < stages.length && s.subs >= stages[s.subStage]) {
+      s.subStage++;
+      pushEvent(s, `🎉 ${stages[s.subStage - 1].toLocaleString()} SUBSCRIBERS — the wrapper prints money`, "good");
+    }
+  }
+
   // VC mandate resolution
   if (s.mandate) {
     const got = s.totalViews - s.mandate.startViews;
@@ -860,6 +889,8 @@ export function step(s: SimState) {
   r.vramNeed = vramNeed;
   r.storageGB = storageGB;
   r.trainStalled = trainStalled;
+  r.subsNet += (subsNet - r.subsNet) * sm;
+  r.saasLatency = saasLatency;
 }
 
 export function shopList(s: SimState) {
diff --git a/src/sim/state.ts b/src/sim/state.ts
index 65b569c..50be7d4 100644
--- a/src/sim/state.ts
+++ b/src/sim/state.ts
@@ -33,6 +33,8 @@ export interface SimState {
   fires: { x: number; y: number; until: number }[];
   adSpend: number; // $/s marketing burn
   lastSpamT: number; // last email-spam blast
+  subs: number; // SaaS subscribers
+  subStage: number; // last milestone toasted
   t: number;
   tick: number;
   cash: number;
@@ -97,6 +99,8 @@ export interface SimState {
     vramNeed: number;
     storageGB: number;
     trainStalled: boolean;
+    subsNet: number; // subscribers/s net growth
+    saasLatency: boolean;
   };
   events: { msg: string; t: number; kind: string }[];
   rng: number;
@@ -109,6 +113,8 @@ export function createState(): SimState {
     fires: [],
     adSpend: 0,
     lastSpamT: -999,
+    subs: 0,
+    subStage: 0,
     t: 0,
     tick: 0,
     cash: BAL.START_CASH,
@@ -156,6 +162,7 @@ export function createState(): SimState {
       powerCost: 0, demandMbps: 0, uplinkMbps: 0, dataMult: 1, maxTemp: BAL.AMBIENT_C,
       adapt: 0, hostIncome: 0, hostTok: 0,
       vramHave: 0, vramNeed: 0, storageGB: 0, trainStalled: false,
+      subsNet: 0, saasLatency: false,
     },
     events: [],
     rng: 0x5109a & 0xffffffff,
diff --git a/src/ui/hud.ts b/src/ui/hud.ts
index ea55b2f..258fe30 100644
--- a/src/ui/hud.ts
+++ b/src/ui/hud.ts
@@ -43,6 +43,7 @@ export class Hud {
   selectedShop: string | null = null;
   lastEventCount = 0;
   lockedCache = "";
+  lastRoom = "bedroom";
 
   constructor(cb: HudCallbacks) {
     this.cb = cb;
@@ -56,6 +57,7 @@ export class Hud {
         <div class="stat"><span class="label">HOTTEST</span><span class="val" id="temp">24°C</span></div>
         <div class="stat"><span class="label">SLOP RATE</span><span class="val" id="tok">0 tok/s</span></div>
         <div class="stat"><span class="label">VIEWS</span><span class="val" id="views">0</span></div>
+        <div class="stat"><span class="label">SUBS</span><span class="val" id="subs">0</span></div>
         <div class="stat"><span class="label">UPLINK</span><span class="val" id="net">0/0 Mbps</span></div>
         <div class="stat"><span class="label">HOSTING</span><span class="val" id="host">$0/s</span></div>
         <div class="stat"><span class="label">VRAM</span><span class="val" id="vram">0GB</span></div>
@@ -131,7 +133,7 @@ export class Hud {
     };
     (this.root.querySelector("#spam") as HTMLButtonElement).onclick = () => cb.onSpam();
     (this.root.querySelector("#move-hq") as HTMLButtonElement).onclick = () => {
-      const mv = MOVES[0];
+      const mv = MOVES.find((m) => m.from === this.lastRoom);
       if (mv && confirm(`${ROOMS[mv.to].name}: ${mv.blurb} — $${mv.cost}?`)) cb.onMove(mv.to);
     };
   }
@@ -244,6 +246,11 @@ export class Hud {
     q("#net").textContent = `${fmt(s.rates.demandMbps, 0)}/${fmt(s.rates.uplinkMbps, 0)} Mbps`;
     (q("#net") as HTMLElement).style.color = s.rates.dataMult < 1 ? "var(--red)" : "";
     q("#views").textContent = fmt(s.totalViews, 0);
+    q("#subs").textContent = fmt(s.subs, 0) + (s.rates.saasLatency ? " ⚠" : "");
+    (q("#subs") as HTMLElement).style.color =
+      s.rates.saasLatency ? "var(--red)" : s.rates.subsNet > 0.01 ? "var(--green)" : "";
+    (q("#subs") as HTMLElement).title =
+      s.rates.saasLatency ? "LATENCY — subscribers churning; free up inference compute" : "SaaS subscribers";
 
     // VC raise chip / mandate progress
     const raise = q("#raise"), mandate = q("#mandate");
@@ -268,10 +275,11 @@ export class Hud {
     const cd = Math.max(0, 60 - (s.t - s.lastSpamT));
     spam.textContent = cd > 0 ? `📧 Spam Blast (${Math.ceil(cd)}s)` : `📧 Spam Blast ($${40 * (s.round + 1)})`;
     spam.classList.toggle("on", cd <= 0);
-    const mv = MOVES.find((m) => m.to !== s.room);
+    this.lastRoom = s.room;
+    const mv = MOVES.find((m) => m.from === s.room);
     (q("#move-hq") as HTMLElement).style.display =
-      mv && s.room === "bedroom" && s.earnedTotal >= mv.unlockAt ? "block" : "none";
-    if (mv) q("#move-hq").textContent = `🚚 Move HQ ($${mv.cost})`;
+      mv && s.earnedTotal >= mv.unlockAt ? "block" : "none";
+    if (mv) q("#move-hq").textContent = `🚚 ${ROOMS[mv.to].name} ($${fmt(mv.cost, 0)})`;
 
     // clap-back window
     const clap = q("#clap");
diff --git a/tools/mb_add.py b/tools/mb_add.py
index c38c99e..3f0eaa2 100644
--- a/tools/mb_add.py
+++ b/tools/mb_add.py
@@ -7,14 +7,15 @@ sys.path.insert(0, str(pathlib.Path(__file__).parent))
 from mb_gen import ROOT, STYLE, flux_spec, run_batch, upload, beat
 
 NEW = [
-    ("extinguisher", "a red CO2 fire extinguisher standing on the floor"),
+    ("immersion_tank", "an open-top industrial immersion cooling tank filled with glowing clear mineral oil, server boards submerged inside, tubes and a small pump, sci-fi green glow"),
+    ("crac_unit", "a tall white industrial precision air conditioning unit for server rooms, floor standing, vent grilles, small status screen"),
 ]
 
 ROOMS = [
-    ("garage", "empty isometric double garage interior for a video game, 2:1 isometric projection, "
-     "two visible walls meeting at back corner, sealed metal roller door on one wall, bare concrete "
-     "floor with subtle square grid lines, exposed stud walls, hanging work light, night time, "
-     "moody blue-purple lighting with one neon strip, no vehicles, no furniture, no people, no text, "
+    ("warehouse", "empty isometric industrial warehouse interior for a video game, 2:1 isometric projection, "
+     "two visible corrugated metal walls meeting at back corner, huge bare concrete floor with subtle "
+     "square grid lines, steel roof trusses hinted at top, high windows, sodium work lights, night time, "
+     "moody blue-purple lighting with cyan accents, no shelving, no vehicles, no people, no text, "
      "clean detailed painterly game art", 1024, 768),
 ]
 
diff --git a/tools/mb_manifest.json b/tools/mb_manifest.json
index 58bed9c..a4aae12 100644
--- a/tools/mb_manifest.json
+++ b/tools/mb_manifest.json
@@ -263,5 +263,25 @@
     "job": "d8ff5530b60b",
     "asset": "4a55508fae90",
     "path": "/Users/jing/Documents/gigaslop/public/assets/gen/extinguisher_cut.png"
+  },
+  "immersion_tank": {
+    "job": "59c0446c8226",
+    "asset": "5830eb712b59",
+    "path": "/Users/jing/Documents/gigaslop/public/assets/gen/immersion_tank.png"
+  },
+  "crac_unit": {
+    "job": "a6d5df83247e",
+    "asset": "9568c9c5917d",
+    "path": "/Users/jing/Documents/gigaslop/public/assets/gen/crac_unit.png"
+  },
+  "immersion_tank_cut": {
+    "job": "e4dde2353757",
+    "asset": "9b2a341a7b99",
+    "path": "/Users/jing/Documents/gigaslop/public/assets/gen/immersion_tank_cut.png"
+  },
+  "crac_unit_cut": {
+    "job": "c15472693bd1",
+    "asset": "00c76075efec",
+    "path": "/Users/jing/Documents/gigaslop/public/assets/gen/crac_unit_cut.png"
   }
 }
\ No newline at end of file