diff --git a/js/app/modalCoordinator.js b/js/app/modalCoordinator.js
index 6b02cec0..f9c8a65d 100644
--- a/js/app/modalCoordinator.js
+++ b/js/app/modalCoordinator.js
@@ -34,6 +34,70 @@ export function createModalCoordinator(deps) {
     BITVID_WEBSITE_URL,
   } = deps;
 
+  // Zap-total badge helpers are LOCAL closures, NOT coordinator methods:
+  // coordinator methods run with `this` bound to the Application, so a
+  // cross-method `this.helper()` call only works when app.js also adds an
+  // explicit delegate for it — a silent landmine (a missing delegate here
+  // threw on EVERY modal open and broke video playback entirely).
+  let modalZapTotalUnsub = null;
+
+  function teardownModalZapTotal() {
+    if (typeof modalZapTotalUnsub === "function") {
+      try {
+        modalZapTotalUnsub();
+      } catch (error) {
+        devLogger.warn("[zapTotals] Failed to tear down modal listener:", error);
+      }
+    }
+    modalZapTotalUnsub = null;
+    const el =
+      typeof document !== "undefined"
+        ? document.getElementById("videoZapTotal")
+        : null;
+    if (el) {
+      el.classList.add("hidden");
+      const text = el.querySelector("[data-zap-total-text]");
+      if (text) {
+        text.textContent = "";
+      }
+    }
+  }
+
+  // Orange sats badge on the modal's meta row (right side; views stay left).
+  // Mirrors the card badge: cached total now (also schedules the batched
+  // receipt fetch), re-rendered when a batch lands, hidden while zero.
+  function subscribeModalZapTotal(pointer) {
+    if (
+      typeof requestVideoZapTotal !== "function" ||
+      typeof getVideoZapTotalSnapshot !== "function" ||
+      typeof onZapTotalsChanged !== "function"
+    ) {
+      return;
+    }
+    const el =
+      typeof document !== "undefined"
+        ? document.getElementById("videoZapTotal")
+        : null;
+    if (!el || !pointer) {
+      return;
+    }
+    const render = () => {
+      const sats = getVideoZapTotalSnapshot(pointer);
+      const text = el.querySelector("[data-zap-total-text]");
+      if (Number.isFinite(sats) && sats > 0) {
+        if (text) {
+          text.textContent = `${formatViewCount(sats)} sats`;
+        }
+        el.classList.remove("hidden");
+      } else {
+        el.classList.add("hidden");
+      }
+    };
+    requestVideoZapTotal(pointer);
+    render();
+    modalZapTotalUnsub = onZapTotalsChanged(render);
+  }
+
   return {
     normalizeModalTrigger(candidate) {
       if (!candidate) {
@@ -120,66 +184,13 @@ export function createModalCoordinator(deps) {
         }
       }
       this.modalViewCountUnsub = null;
-      this.teardownModalZapTotal();
+      teardownModalZapTotal();
       if (this.videoModal) {
         this.videoModal.updateViewCountLabel("\u2013 views");
         this.videoModal.setViewCountPointer(null);
       }
     },
 
-    teardownModalZapTotal() {
-      if (typeof this.modalZapTotalUnsub === "function") {
-        try {
-          this.modalZapTotalUnsub();
-        } catch (error) {
-          devLogger.warn("[zapTotals] Failed to tear down modal listener:", error);
-        }
-      }
-      this.modalZapTotalUnsub = null;
-      const el =
-        typeof document !== "undefined"
-          ? document.getElementById("videoZapTotal")
-          : null;
-      if (el) {
-        el.classList.add("hidden");
-        const text = el.querySelector("[data-zap-total-text]");
-        if (text) {
-          text.textContent = "";
-        }
-      }
-    },
-
-    // Orange sats badge on the modal's meta row (right side; views stay left).
-    // Mirrors the card badge: cached total now (also schedules the batched
-    // receipt fetch), re-rendered when a batch lands, hidden while zero.
-    subscribeModalZapTotal(pointer) {
-      if (typeof requestVideoZapTotal !== "function") {
-        return;
-      }
-      const el =
-        typeof document !== "undefined"
-          ? document.getElementById("videoZapTotal")
-          : null;
-      if (!el || !pointer) {
-        return;
-      }
-      const render = () => {
-        const sats = getVideoZapTotalSnapshot(pointer);
-        const text = el.querySelector("[data-zap-total-text]");
-        if (Number.isFinite(sats) && sats > 0) {
-          if (text) {
-            text.textContent = `${formatViewCount(sats)} sats`;
-          }
-          el.classList.remove("hidden");
-        } else {
-          el.classList.add("hidden");
-        }
-      };
-      requestVideoZapTotal(pointer);
-      render();
-      this.modalZapTotalUnsub = onZapTotalsChanged(render);
-    },
-
     subscribeModalViewCount(pointer, pointerKey) {
       const viewEl = this.videoModal?.getViewCountElement() || null;
       if (!viewEl) {
@@ -196,7 +207,7 @@ export function createModalCoordinator(deps) {
         this.videoModal.updateViewCountLabel("Loading views\u2026");
         this.videoModal.setViewCountPointer(pointerKey);
       }
-      this.subscribeModalZapTotal(pointer);
+      subscribeModalZapTotal(pointer);
       try {
         const token = subscribeToVideoViewCount(pointer, ({ total, status, partial }) => {
           const latestViewEl = this.videoModal?.getViewCountElement() || null;
diff --git a/tests/modal-coordinator-zap-badge.test.mjs b/tests/modal-coordinator-zap-badge.test.mjs
new file mode 100644
index 00000000..a8b17ab5
--- /dev/null
+++ b/tests/modal-coordinator-zap-badge.test.mjs
@@ -0,0 +1,108 @@
+// Regression for "clicking a video no longer opens the player": coordinator
+// methods run with `this` bound to the APPLICATION (bindCoordinator), so a
+// cross-method `this.helper()` call inside the coordinator only works when
+// app.js also adds an explicit delegate — the zap-badge helpers were plain
+// methods, `this.subscribeModalZapTotal` didn't exist on the app, and EVERY
+// modal open threw. This test drives subscribeModalViewCount through the REAL
+// bindCoordinator with ONLY the delegates app.js actually defines, so any
+// future cross-method `this.` call without a delegate fails here first.
+//
+// test_integrity_note:
+//   change_type: ["new_tests"]
+//   scenarios:
+//     - id: SCN-modal-open-no-missing-delegate
+//       given: "a coordinator bound to an app stub exposing only app.js's real modal delegates"
+//       when: "subscribeModalViewCount runs (the modal-open path) and teardown runs (close path)"
+//       then: "no TypeError; the zap badge renders from the shared store and clears on teardown"
+//   observable_outcomes:
+//     - "subscribeModalViewCount does not throw (the user-facing 'video will not open' bug)"
+//     - "badge hidden at zero, revealed with sats after a receipt batch, cleared on teardown"
+//   determinism_controls:
+//     - "JSDOM; scripted subscription-manager double; store flushed manually"
+//   anti_cheat_rationale:
+//     prevents: ["over-mocking internal logic", "hard-coded return value"]
+//   relaxation:
+//     did_relax_any_assertion: false
+
+import "./test-helpers/setup-localstorage.mjs";
+import test from "node:test";
+import { strict as assert } from "node:assert";
+import { JSDOM } from "jsdom";
+import { createModalCoordinator } from "../js/app/modalCoordinator.js";
+import bindCoordinator from "../js/app/bindCoordinator.js";
+import zapTotalsStore, {
+  initZapTotals,
+  requestVideoZapTotal,
+  getVideoZapTotalSnapshot,
+  onZapTotalsChanged,
+} from "../js/zapTotals.js";
+import { formatViewCount } from "../js/viewCounter.js";
+
+const A1 = "30078:" + "c".repeat(64) + ":video-1";
+
+test("modal open path survives binding and drives the zap badge", async () => {
+  const dom = new JSDOM(
+    '<!DOCTYPE html><body><span id="videoZapTotal" class="hidden"><span data-zap-total-text></span></span></body>',
+    { pretendToBeVisual: true },
+  );
+  global.document = dom.window.document;
+
+  let receipts = [];
+  initZapTotals({
+    nostrClient: {
+      relays: ["wss://relay.example"],
+      getSubscriptionManager: () => ({ list: async () => receipts }),
+    },
+    tools: { nip57: { getSatoshisAmountFromBolt11: () => NaN } },
+  });
+
+  const coordinator = createModalCoordinator({
+    devLogger: { warn: () => {}, log: () => {}, error: () => {} },
+    subscribeToVideoViewCount: () => "token-1",
+    unsubscribeFromVideoViewCount: () => {},
+    formatViewCount,
+    requestVideoZapTotal,
+    getVideoZapTotalSnapshot,
+    onZapTotalsChanged,
+  });
+
+  // App stub with ONLY the delegates app.js really defines for this path.
+  const app = {
+    videoModal: {
+      getViewCountElement: () => dom.window.document.createElement("span"),
+      updateViewCountLabel: () => {},
+      setViewCountPointer: () => {},
+    },
+    formatViewCountLabel: (n) => `${n} views`,
+  };
+  app._modal = bindCoordinator(app, coordinator);
+  app.teardownModalViewCountSubscription = (...args) =>
+    app._modal.teardownModalViewCountSubscription(...args);
+  app.subscribeModalViewCount = (...args) =>
+    app._modal.subscribeModalViewCount(...args);
+
+  const pointer = ["a", A1];
+  // The bug: this line threw "this.subscribeModalZapTotal is not a function".
+  app.subscribeModalViewCount(pointer, `a:${A1}`);
+
+  const badge = dom.window.document.getElementById("videoZapTotal");
+  assert.equal(badge.classList.contains("hidden"), true, "zero total stays hidden");
+
+  receipts = [
+    {
+      id: "r1",
+      kind: 9735,
+      tags: [["a", A1], ["description", JSON.stringify({ tags: [["amount", "21000"]] })]],
+    },
+  ];
+  await zapTotalsStore.flush();
+  assert.equal(badge.classList.contains("hidden"), false, "receipts reveal the badge");
+  assert.match(
+    badge.querySelector("[data-zap-total-text]").textContent,
+    /21 sats/,
+  );
+
+  // Modal close path (also used to throw via this.teardownModalZapTotal).
+  app.teardownModalViewCountSubscription();
+  assert.equal(badge.classList.contains("hidden"), true, "teardown clears the badge");
+});