diff --git a/scripts/frank-dragoon.env b/scripts/frank-dragoon.env
index c662000..89548dd 100644
--- a/scripts/frank-dragoon.env
+++ b/scripts/frank-dragoon.env
@@ -114,10 +114,13 @@ HALOGEN_NPU_MODELS=qwen3-embedding-0.6b
 FRANK_DRAGOON_NPU_DIR=/home/dank/models/halogen-v2-abliterated/npu
 # Node paths and the XRT directory are variables so the bats seam can drive
 # these gates on a box with no NPU. Ubuntu's distro XRT (libxrt2 + libxrt-npu2)
-# is mounted FILE BY FILE and TWICE EACH — once where the image looks for XRT,
-# once at its own path, because those libraries find each other at their install
-# path; the vendor forbids mounting an /opt/xilinx/xrt of symlinks into the
-# system dir, which dangle inside the container.
+# is mounted FILE BY FILE and THREE TIMES EACH — where the image looks for XRT
+# (/opt/xilinx/xrt/lib), at its own path (those libraries find each other at
+# their install path), and at /opt/xilinx/lib/<multiarch>/ (the NPU child
+# searches that third prefix; without it the lane dies naming it and the
+# supervisor takes the container down — 2026-10-21 boot loop). The basename of
+# this directory IS the multiarch name. The vendor forbids mounting an
+# /opt/xilinx/xrt of symlinks into the system dir, which dangle in the container.
 FRANK_DRAGOON_DEV_ACCEL=/dev/accel/accel0
 FRANK_DRAGOON_XRT_DIR=/usr/lib/x86_64-linux-gnu
 # sysfs root the fabric-clock preflight reads (same knob the vendor's
diff --git a/scripts/serve-frank-dragoon.sh b/scripts/serve-frank-dragoon.sh
index cb5e6c9..e2fea17 100755
--- a/scripts/serve-frank-dragoon.sh
+++ b/scripts/serve-frank-dragoon.sh
@@ -136,10 +136,17 @@ fi
 #      The engine re-checks size+sha256 against that catalog at boot; it cannot
 #      fetch anything here because /models is read-only and HALOGEN_DOWNLOAD
 #      stays unset — no outbound connection at boot),
-#   2. the distro XRT's three libraries, each mounted twice (where the image
-#      looks for XRT, and at its own path — the libraries find each other there;
-#      an /opt/xilinx/xrt of symlinks into the system dir dangles inside the
-#      container, which the vendor calls out explicitly),
+#   2. the distro XRT's three libraries, each mounted THREE times: where the
+#      image looks for XRT (/opt/xilinx/xrt/lib), at their own path (the
+#      libraries find each other there), and at /opt/xilinx/lib/<multiarch>
+#      — the NPU child searches that third prefix too, and since the host's
+#      libxrt2 was reconfigured 2026-10-20 it is the ONLY prefix the child
+#      names: omitting it crashes the lane with `No such library
+#      '/opt/xilinx/lib/x86_64-linux-gnu/libxrt_core.so.2'` and the engine
+#      supervisor takes the dead lane down on the whole container (measured
+#      2026-10-21: 88-restart boot loop). Real files only — an /opt/xilinx/xrt
+#      of symlinks into the system dir dangles inside the container, which the
+#      vendor calls out explicitly),
 #   3. the GPU fabric clock HELD: on Strix Halo the iGPU and the NPU co-running
 #      hang the machine while FCLK changes speed, and the engine refuses to
 #      start when it moves — it cannot read host sysfs from inside the
@@ -190,7 +197,9 @@ if [ -n "$NPU_MODELS" ]; then
             exit 1
         fi
         REAL="$(readlink -f "$XRT_DIR/$L")"
-        NPU_ARGS+=(-v "$REAL:/opt/xilinx/xrt/lib/$L:ro" -v "$REAL:$XRT_DIR/$L:ro")
+        MULTIARCH="${XRT_DIR##*/}"
+        NPU_ARGS+=(-v "$REAL:/opt/xilinx/xrt/lib/$L:ro" -v "$REAL:$XRT_DIR/$L:ro"
+                   -v "$REAL:/opt/xilinx/lib/$MULTIARCH/$L:ro")
     done
     HELD=0
     for D in "$SYSFS"/class/drm/card*/device; do
diff --git a/serverAppConfigs-docs/LLM/frank-dragoon.md b/serverAppConfigs-docs/LLM/frank-dragoon.md
index a0077fc..04c8424 100644
--- a/serverAppConfigs-docs/LLM/frank-dragoon.md
+++ b/serverAppConfigs-docs/LLM/frank-dragoon.md
@@ -256,9 +256,14 @@ lane is **armed and serving** since 2026-10-19 (`HALOGEN_NPU_MODELS=qwen3-embedd
    (`dankclaw/udev/98-halogen-npu-access.rules`, installed and re-triggered by the deployer, `0666` like the GPU
    compute nodes beside it); the serve script refuses any node that is not other-accessible, so the fault cannot
    return as a crash-loop.
-2. The host's XRT reachable inside: there is **no `/opt/xilinx/xrt`** here — distro packages put the three files the
-   container needs (`libxrt_coreutil.so.2`, `libxrt_core.so.2`, `libxrt_driver_xdna.so.2`) in
-   `/usr/lib/x86_64-linux-gnu`, where all three exist.
+2. The host's XRT reachable inside, at **THREE prefixes per library**: there is **no `/opt/xilinx/xrt`** here —
+   distro packages put the three files the container needs (`libxrt_coreutil.so.2`, `libxrt_core.so.2`,
+   `libxrt_driver_xdna.so.2`) in `/usr/lib/x86_64-linux-gnu`. The serve script mounts each REAL file (never a
+   symlink) at `/opt/xilinx/xrt/lib/`, at its own path, AND at `/opt/xilinx/lib/<multiarch>/` — the NPU child
+   searches that third prefix and a missing one is fatal: since the host's `libxrt2` was reconfigured
+   2026-10-20 the child died with `No such library '/opt/xilinx/lib/x86_64-linux-gnu/libxrt_core.so.2'` and the
+   engine supervisor took the WHOLE container down on it (88-restart loop, chat dead beside a healthy GPU line).
+   A dead lane is not survivable here — arm the lane only with all three prefixes mounted.
 3. **The GPU fabric clock held at its top level, or the engine refuses to start.** GPU and NPU work share the die:
    while `pp_dpm_fclk` is changing speed, concurrent GPU work can hang the machine and corrupt NPU results. The
    engine holds the clock itself only when it runs as root with `/sys` mounted; `frank-dragoon` is a **rootless**
diff --git a/tests/frank_dragoon_unit.bats b/tests/frank_dragoon_unit.bats
index 715fd63..e8fcfb2 100755
--- a/tests/frank_dragoon_unit.bats
+++ b/tests/frank_dragoon_unit.bats
@@ -430,9 +430,12 @@ npu_fixture() {
     # the stock root:render 0660 mode, and the serve gate checks exactly that.
     touch "$TEST_TMP/accel0"
     chmod 666 "$TEST_TMP/accel0"
-    mkdir -p "$TEST_TMP/xrt"
+    # basename carries a multiarch shape: the third mount prefix is derived
+    # from the XRT dir's basename (the NPU child searches
+    # /opt/xilinx/lib/<multiarch>/, measured 2026-10-21).
+    mkdir -p "$TEST_TMP/x86_64-linux-gnu"
     for l in libxrt_coreutil.so.2 libxrt_core.so.2 libxrt_driver_xdna.so.2; do
-        touch "$TEST_TMP/xrt/$l"
+        touch "$TEST_TMP/x86_64-linux-gnu/$l"
     done
     mkdir -p "$TEST_TMP/npu/qwen3-embedding-0.6b/devices"
     mkdir -p "$TEST_TMP/sys/class/drm/card1/device"
@@ -442,7 +445,7 @@ npu_fixture() {
         "HALOGEN_NPU_MODELS=qwen3-embedding-0.6b"
         "FRANK_DRAGOON_NPU_DIR=$TEST_TMP/npu"
         "FRANK_DRAGOON_DEV_ACCEL=$TEST_TMP/accel0"
-        "FRANK_DRAGOON_XRT_DIR=$TEST_TMP/xrt"
+        "FRANK_DRAGOON_XRT_DIR=$TEST_TMP/x86_64-linux-gnu"
         "FRANK_DRAGOON_SYSFS=$TEST_TMP/sys"
     )
 }
@@ -472,11 +475,15 @@ $(cat "$TEST_TMP/serve.log")"
     ! grep -q 'accel0' "$TEST_TMP/serve.log"
 }
 
-@test "the lane arms the accel node, the staged model dir and each XRT library twice" {
-    # Each library mounts at the image's XRT path AND at its own path: the
-    # distro libraries find each other where they were installed, and an
-    # /opt/xilinx/xrt of symlinks into the system dir dangles inside the
-    # container (the vendor calls that out by name).
+@test "the lane arms the accel node, the staged model dir and each XRT library three times" {
+    # Each library mounts at the image's XRT path, at its own path (the distro
+    # libraries find each other where they were installed), and at
+    # /opt/xilinx/lib/<multiarch>/ — the prefix the NPU child searches and
+    # names when it is missing (`No such library
+    # '/opt/xilinx/lib/x86_64-linux-gnu/libxrt_core.so.2'`, measured
+    # 2026-10-21: the lane died and the supervisor took the whole container
+    # with it, 88-restart loop). An /opt/xilinx/xrt of symlinks into the
+    # system dir dangles inside the container (the vendor calls that out).
     podman_stub
     good_env
     npu_fixture
@@ -491,8 +498,9 @@ $(cat "$TEST_TMP/serve.log")"
     [[ "$output" != *":/models/npu"* ]]
     [[ "$output" == *"-e HALOGEN_NPU_MODELS=qwen3-embedding-0.6b"* ]]
     for l in libxrt_coreutil.so.2 libxrt_core.so.2 libxrt_driver_xdna.so.2; do
-        [[ "$output" == *"-v $TEST_TMP/xrt/$l:/opt/xilinx/xrt/lib/$l:ro"* ]]
-        [[ "$output" == *"-v $TEST_TMP/xrt/$l:$TEST_TMP/xrt/$l:ro"* ]]
+        [[ "$output" == *"-v $TEST_TMP/x86_64-linux-gnu/$l:/opt/xilinx/xrt/lib/$l:ro"* ]]
+        [[ "$output" == *"-v $TEST_TMP/x86_64-linux-gnu/$l:$TEST_TMP/x86_64-linux-gnu/$l:ro"* ]]
+        [[ "$output" == *"-v $TEST_TMP/x86_64-linux-gnu/$l:/opt/xilinx/lib/x86_64-linux-gnu/$l:ro"* ]]
     done
     # The Flash payload still rides the same container: the lane is additive.
     [[ "$output" == *"-e HALOGEN_CHECKPOINT=/models/qwen.hgn"* ]]
@@ -567,7 +575,7 @@ $(cat "$TEST_TMP/serve.log")"
     podman_stub
     good_env
     npu_fixture
-    rm "$TEST_TMP/xrt/libxrt_driver_xdna.so.2"
+    rm "$TEST_TMP/x86_64-linux-gnu/libxrt_driver_xdna.so.2"
     run_with_log
     [ "$status" -ne 0 ]
     [[ "$output" == *"libxrt_driver_xdna.so.2 missing"* ]]