diff --git a/.claude-plugin/marketplace.json b/.claude-plugin/marketplace.json
index e028f5d68..28f841dbf 100644
--- a/.claude-plugin/marketplace.json
+++ b/.claude-plugin/marketplace.json
@@ -8,7 +8,7 @@
   "plugins": [
     {
       "name": "mh",
-      "version": "1.1.393",
+      "version": "1.1.394",
       "source": ".",
       "description": "A Claude Code harness that composes mattpocock-skills instead of duplicating it. Nine computational deny/ask gates (irrecoverable commands, subagent git guard, subagent spawn guard, task-complete separation, test integrity, config-write guard, secret-content scan, codex-setup guard, routine-trigger guard) plus a SubagentStop verdict-check gate, a 4 KB METHODOLOGY injected at SessionStart, and memory-lint for the auto-memory store.",
       "author": {
diff --git a/.claude-plugin/plugin.json b/.claude-plugin/plugin.json
index 44542299b..29950076b 100644
--- a/.claude-plugin/plugin.json
+++ b/.claude-plugin/plugin.json
@@ -2,7 +2,7 @@
   "$schema": "https://json.schemastore.org/claude-code-plugin-manifest.json",
   "name": "mh",
   "displayName": "Method Harness",
-  "version": "1.1.393",
+  "version": "1.1.394",
   "description": "A Claude Code harness that composes mattpocock-skills instead of duplicating it. Nine computational deny/ask gates (irrecoverable commands, subagent git guard, subagent spawn guard, task-complete separation, test integrity, config-write guard, secret-content scan, codex-setup guard, routine-trigger guard) plus a SubagentStop verdict-check gate, a 4 KB METHODOLOGY injected at SessionStart, and memory-lint for the auto-memory store.",
   "author": {
     "name": "wasikarn"
diff --git a/docs/reference/env-vars.md b/docs/reference/env-vars.md
index 7d79ac64e..78f01b1d5 100644
--- a/docs/reference/env-vars.md
+++ b/docs/reference/env-vars.md
@@ -24,6 +24,7 @@ under `env`, never in a committed file.
 | `GAUNTLET_JOBS` | `scripts/run-gauntlet.sh` | Test files run in parallel (default `4`, or `1` when `CI` is set). |
 | `GAUNTLET_SHARD` | `scripts/run-gauntlet.sh` | `i/N`: run only shard `i` of `N` (GH #400); anything else fails. Unset before child tests run. |
 | `GAUNTLET_LOCK_DIR`, `GAUNTLET_LOCK_WAIT_SECS`, `GAUNTLET_LOCK_POLL`, `GAUNTLET_LOCK_MAX_AGE`, `GAUNTLET_LOCK_NOPID_SECS` | `scripts/_lib/gauntlet-lock.sh` | Machine-wide gauntlet queue: lock dir (default `~/.cache/mh/gauntlet.lock`), max wait before running unlocked (`1800` s), poll (`5` s plus jitter), age past which a lock is stale (`3600` s), age a pid-less lock dir must reach to count as a crash leftover (`60` s). |
+| `GAUNTLET_STRAY_MIN_SECS`, `GAUNTLET_STRAY_MIN_CPU` | `scripts/_lib/stray-procs.sh` (called by `scripts/run-gauntlet.sh`) | Thresholds for the warn-only stray-process report: your processes older than this many seconds (default `1800`) are grouped by command name, and a group whose %CPU sums to this or more (default `80`) is named before the layers run and again on failure. A non-numeric value falls back to the default. |
 | `MH_GAUNTLET_LOCK_OWNER` | `scripts/_lib/gauntlet-lock.sh` | Exported by the lock holder with its pid, so a child (a test that runs the pre-push hook) skips the queue instead of deadlocking. Not a user knob. |
 | `MERGE_PR_LOAD_MAX` | `scripts/merge-pr.sh` | Load average below which the script merges (default `4`); `tests/scripts/test-merge-pr.sh` sets `4` explicitly. |
 | `MERGE_PR_LOAD_WAIT_SECS` | `scripts/merge-pr.sh` | Seconds the script waits for load to drop before it fails with the load figure (default `900`); the test sets `0`. |
diff --git a/docs/reference/repo-gotchas.md b/docs/reference/repo-gotchas.md
index 744f747e0..c8b6a27fe 100644
--- a/docs/reference/repo-gotchas.md
+++ b/docs/reference/repo-gotchas.md
@@ -160,6 +160,15 @@ already set alone.
   names non-UUID ids but does not drop them). Probe with
   `MH_GATE_JOURNAL_PATH=/dev/null` (or a scratch file when you want to read the row back), and
   use `scripts/gate-differential.sh` for old-vs-new comparisons, which already isolates it.
+- **Background load runs go in a bash file, with explicit PIDs.** The Bash tool's shell is zsh:
+  `wait $pids` does not word-split, and under `zsh -c` `kill $(jobs -p)` finds no jobs, so the
+  workers outlive the run. Twice this left a flood behind (289 processes, load ~248, 2026-10-05;
+  4 `yes` at 100% CPU for ~4 h, 2026-10-25) that failed every session's timing rows. Write the
+  run as a file and start it with `bash <file>`, collect `pids+=($!)`, `kill "${pids[@]}"` in a
+  `trap ... EXIT`, then confirm no worker is left and the load has dropped. `run-gauntlet.sh` now
+  names long-running CPU-heavy process groups of yours, a flood of low-CPU workers included
+  (`scripts/_lib/stray-procs.sh`, warn-only), but it can only catch a stray after the fact; killing
+  one that a peer session owns is the operator's call.
 
 ## Research: check qmd before web search
 
diff --git a/scripts/_lib/stray-procs.sh b/scripts/_lib/stray-procs.sh
new file mode 100644
index 000000000..10d7c0602
--- /dev/null
+++ b/scripts/_lib/stray-procs.sh
@@ -0,0 +1,65 @@
+#!/usr/bin/env bash
+# stray-procs.sh — name the operator's own long-running CPU-heavy process groups (GH #158). Two
+# stress runs typed into the Bash tool's zsh left their workers behind: 289 processes at load ~248
+# (2026-10-05, `wait $pids` does not word-split in zsh) and 4 `yes` at 100% CPU for ~4 h
+# (2026-10-25, `kill $(jobs -p)` found no jobs under `zsh -c`). Every push's timing rows failed
+# until someone spotted them. This shortens detection to the next gauntlet run. Source it, then:
+#   stray_procs_report
+# Your processes older than GAUNTLET_STRAY_MIN_SECS (1800) are grouped by command name, and a group
+# whose %CPU sums to GAUNTLET_STRAY_MIN_CPU (80) or more is listed on stderr with the load average.
+# Summing per group catches both shapes: one process at full CPU, and a flood of many processes at a
+# few percent each; many idle copies (macOS keeps 40+ SetStoreUpdateService) sum to ~0 and stay quiet.
+# It never kills anything (a process may belong to a peer session's live run; killing it is the
+# operator's call) and never returns non-zero, so a `set -e` caller is never aborted; when ps fails it
+# says so in one line and skips. Detection is by behaviour, not by name: a long build at full CPU is
+# named too, which is the point of a warning. The 30 min default skips a busy headless `claude` run
+# (named at 13 min on the first live run); the strays this targets ran for hours. Bash 3.2.
+
+# A numeric env setting, or its default when unset or not a whole number: a typo such as "1h" must
+# not reach awk as a threshold (same rule as _gl_num in gauntlet-lock.sh).
+_sp_num() {
+  case "${1:-}" in ''|*[!0-9]*) echo "$2" ;; *) echo "$1" ;; esac
+}
+
+# Your own processes as "pid etime %cpu command" (etime: [[dd-]hh:]mm:ss; macOS ps has no etimes).
+_sp_ps() { ps -U "$(id -u)" -o pid=,etime=,%cpu=,command= 2>/dev/null; }
+
+_sp_load() {
+  uptime 2>/dev/null | sed 's/.*load average[s]*: *//' | awk -F'[ ,]+' '{print $1}'
+}
+
+stray_procs_report() {
+  local min_secs min_cpu rows found load
+  min_secs=$(_sp_num "${GAUNTLET_STRAY_MIN_SECS:-}" 1800)
+  min_cpu=$(_sp_num "${GAUNTLET_STRAY_MIN_CPU:-}" 80)
+  rows=$(_sp_ps) || { echo "gauntlet: stray-process check skipped (ps failed)" >&2; return 0; }
+  found=$(printf '%s\n' "$rows" | awk -v ms="$min_secs" -v mc="$min_cpu" '
+    NF >= 4 {
+      e = $2; d = 0
+      if (index(e, "-")) { d = substr(e, 1, index(e, "-") - 1); e = substr(e, index(e, "-") + 1) }
+      n = split(e, t, ":"); s = 0
+      for (i = 1; i <= n; i++) s = s * 60 + t[i]
+      s += d * 86400
+      if (s < ms) next
+      k = $4; sub(".*/", "", k)
+      if (!(k in cnt)) { keys[++nk] = k; cmd[k] = $4; for (i = 5; i <= NF; i++) cmd[k] = cmd[k] " " $i }
+      cnt[k]++; sum[k] += $3
+      if (cnt[k] <= 8) pids[k] = pids[k] " " $1; else if (cnt[k] == 9) pids[k] = pids[k] " ..."
+      if (s > old[k]) { old[k] = s; oldest[k] = $2 }
+    }
+    END {
+      for (j = 1; j <= nk; j++) {
+        k = keys[j]
+        if (sum[k] < mc) continue
+        printf "  %s: %d process%s at %.1f%% CPU, oldest %s, pids%s; %s\n", k, cnt[k], (cnt[k] == 1 ? "" : "es"), sum[k], oldest[k], pids[k], substr(cmd[k], 1, 100)
+      }
+    }') || { echo "gauntlet: stray-process check skipped (awk failed)" >&2; return 0; }
+  [ -n "$found" ] || return 0
+  load=$(_sp_load) || load=""
+  {
+    echo "gauntlet: warning: load ${load:-unknown}; these process groups of yours have run ${min_secs}s+ at ${min_cpu}%+ CPU in total."
+    echo "gauntlet: a leftover stress run fails the timing rows; check them before re-running (this never kills anything):"
+    printf '%s\n' "$found"
+  } >&2
+  return 0
+}
diff --git a/scripts/run-gauntlet.sh b/scripts/run-gauntlet.sh
index 15dcfb08a..cc695fb9b 100755
--- a/scripts/run-gauntlet.sh
+++ b/scripts/run-gauntlet.sh
@@ -187,6 +187,12 @@ run_hook_tests() {
   return "$rc"
 }
 
+# GH #158: name leftover CPU-heavy processes (a stray stress run) before the timing rows run, and
+# again on failure, so a load flake can be told from a regression. Warn-only, never fails the run.
+# shellcheck source=_lib/stray-procs.sh
+. "$ROOT/scripts/_lib/stray-procs.sh"
+stray_procs_report
+
 p1="" p2=""
 if [ -z "$shard" ] || [ "${shard%/*}" -eq 1 ]; then
   # check-observer-contract.sh (GH #443): the mh module stays a turn.complete observer.
@@ -214,6 +220,7 @@ if [ "$fail" -eq 0 ]; then
   echo "gauntlet: all layers passed"
 else
   echo "gauntlet: FAILED (full logs kept at $LOG)" >&2
+  stray_procs_report  # before the lists: the last line stays the failing: list (GH #387)
   /usr/bin/grep '^failed-at:' "$LOG/tests" >&2
   /usr/bin/grep '^failing:' "$LOG/tests" >&2
 fi
diff --git a/tests/scripts/test-gauntlet-failed-summary.sh b/tests/scripts/test-gauntlet-failed-summary.sh
index a0787146f..4cded10ce 100644
--- a/tests/scripts/test-gauntlet-failed-summary.sh
+++ b/tests/scripts/test-gauntlet-failed-summary.sh
@@ -71,7 +71,15 @@ elif [ -z "$LOGDIR" ]; then
   bad "mktemp -d failed for the log dir"
 else
   printf -- '--- tests/x.sh\nnoise\nfailed-at: tests/scripts/test-red.sh: ❌ row\nfailing: tests/scripts/test-red.sh\n' >"$LOGDIR/tests"
-  out=$(bash -c "LOG='$LOGDIR'; fail=1; $TAIL" 2>&1)
+  # stray_procs_report reads the real ps; a stub stands in, and its line proves the call runs.
+  out=$(bash -c "LOG='$LOGDIR'; fail=1; stray_procs_report() { echo 'gauntlet: warning: stub'; }; $TAIL" 2>&1)
+  stub_at=$(printf '%s\n' "$out" | /usr/bin/grep -n -m1 -F 'gauntlet: warning: stub' | cut -d: -f1)
+  list_at=$(printf '%s\n' "$out" | /usr/bin/grep -n -m1 '^failing:' | cut -d: -f1)
+  if [ -n "$stub_at" ] && [ -n "$list_at" ] && [ "$stub_at" -lt "$list_at" ]; then
+    ok "a failed run reports stray processes, above the failing: list (GH #158)"
+  else
+    bad "no stray report above the failing: list (stub line '$stub_at', failing: line '$list_at'): <$out>"
+  fi
   last=$(printf '%s\n' "$out" | tail -n 1)
   if /usr/bin/grep -qF 'failing: tests/scripts/test-red.sh' <<<"$last"; then
     ok "the last line of a failed run repeats the failing: list"
diff --git a/tests/scripts/test-gauntlet-stray-procs.sh b/tests/scripts/test-gauntlet-stray-procs.sh
new file mode 100755
index 000000000..15105242e
--- /dev/null
+++ b/tests/scripts/test-gauntlet-stray-procs.sh
@@ -0,0 +1,93 @@
+#!/usr/bin/env bash
+# test-gauntlet-stray-procs.sh — GH #158: scripts/_lib/stray-procs.sh names the operator's own
+# long-running CPU-heavy process groups. Two real floods drive the rows: 4 `yes` at 100% CPU for
+# ~4 h (2026-10-25) and 289 stress workers at load ~248, about 4% each on 12 cores (2026-10-05).
+# Each case sources the library in a fresh `bash -c` and replaces its ps/load readers with fixture
+# text, so no row depends on real CPU time.
+set -uo pipefail
+# An operator may set these in settings.json env; the rows below assume the defaults.
+unset GAUNTLET_STRAY_MIN_SECS GAUNTLET_STRAY_MIN_CPU
+HERE="$(cd -P "$(dirname "$0")" && pwd)"
+LIB="$HERE/../../scripts/_lib/stray-procs.sh"
+GAUNTLET="$HERE/../../scripts/run-gauntlet.sh"
+pass=0; fail=0
+ok()  { pass=$((pass + 1)); echo "  PASS: $1"; }
+bad() { fail=$((fail + 1)); echo "  FAIL: $1" >&2; }
+
+echo "=== stray-procs: name leftover CPU-heavy process groups (GH #158) ==="
+
+# pid etime %cpu command, as `ps -o pid=,etime=,%cpu=,command=` prints them.
+ROWS='82797     04:27:19  99.4 yes
+82799     04:27:19  99.0 yes
+ 1234   1-00:00:30  85.0 /usr/bin/python3 stress.py --n 4
+ 2222        30:00 250.0 node build
+ 3333        00:30 100.0 yes
+ 4444     05:00:00   2.0 /bin/zsh
+ 5555        29:59  99.0 sleeper
+ 6666     01:00:00  80.0 exact80
+ 7777     01:00:00  79.9 under80'
+for i in $(seq 1 30); do ROWS="$ROWS
+ $((9000 + i))        45:00   4.0 /tmp/racer.sh"; done
+for i in $(seq 1 43); do ROWS="$ROWS
+ $((8000 + i))     05:00:00   0.0 /usr/libexec/SetStoreUpdateService"; done
+
+# run <ps-body> [env...]: report on stdout+stderr, then "rc=<n>".
+run() {
+  local body=$1; shift
+  env "$@" ROWS="$ROWS" bash -c ". '$LIB'
+_sp_ps() { $body; }
+_sp_load() { echo 6.25; }
+stray_procs_report; echo \"rc=\$?\"" 2>&1
+}
+line() { printf '%s\n' "$out" | /usr/bin/grep "^  $1:"; }
+
+out=$(run 'printf "%s\n" "$ROWS"')
+l=$(line yes)
+case "$l" in *"2 processes"*"pids 82797 82799"*) ok "two 4 h yes at 99% are one group with both pids" ;; *) bad "yes group wrong: <$l> in $out" ;; esac
+case "$l" in *3333*) bad "a 30 s yes joined the old yes group: <$l>" ;; *) ok "a young copy of the same command is left out of the group" ;; esac
+case "$(line python3)" in *"1 process"*"pids 1234"*"stress.py --n 4"*) ok "a dd-hh:mm:ss elapsed counts its days (1-00:00:30), and the command line is shown" ;; *) bad "1-day row missing: $out" ;; esac
+case "$(line node)" in *"pids 2222"*) ok "exactly the minimum age and %CPU above 100 (multi-core) count" ;; *) bad "boundary age row missing: $out" ;; esac
+case "$(line exact80)" in *"pids 6666"*) ok "exactly the minimum %CPU counts" ;; *) bad "80.0% row missing: $out" ;; esac
+case "$out" in *under80*) bad "a 79.9% process was named: $out" ;; *) ok "just under the minimum %CPU is not named" ;; esac
+case "$(line racer.sh)" in *"30 processes at 120"*) ok "30 workers at 4% each sum to one named group (the 2026-10-05 flood shape)" ;; *) bad "low-CPU flood not named: $out" ;; esac
+case "$out" in *SetStoreUpdateService*) bad "43 idle copies were named: $out" ;; *) ok "many idle copies of one command are not named" ;; esac
+case "$out" in *zsh*) bad "a 2% process was named: $out" ;; *) ok "a long but idle process is not named" ;; esac
+case "$out" in *sleeper*) bad "a 29:59 process was named: $out" ;; *) ok "one second under the minimum age is not named" ;; esac
+case "$out" in *"load 6.25"*) ok "the warning states the load average" ;; *) bad "load missing: $out" ;; esac
+case "$out" in *"rc=0") ok "it returns 0 even when it finds strays (a warning, never a gate)" ;; *) bad "non-zero rc: $out" ;; esac
+
+out=$(env ROWS="$ROWS" bash -c ". '$LIB'; _sp_ps() { printf '%s\n' \"\$ROWS\"; }; stray_procs_report" 2>/dev/null)
+[ -z "$out" ] && ok "the warning goes to stderr, never stdout (a caller may capture stdout)" || bad "stdout got: $out"
+
+out=$(run 'printf "%s\n" " 3333 00:30 100.0 yes"')
+[ "$out" = "rc=0" ] && ok "no strays: silent, rc 0" || bad "no-stray run printed: $out"
+
+out=$(run 'return 1')
+case "$out" in "gauntlet: stray-process check skipped (ps failed)"*"rc=0") ok "ps failing: one diagnostic line, rc 0" ;; *) bad "ps failure not reported: $out" ;; esac
+
+out=$(env ROWS="$ROWS" bash -c ". '$LIB'; _sp_ps() { printf '%s\n' \"\$ROWS\"; }; _sp_load() { return 1; }; stray_procs_report" 2>&1)
+case "$out" in *"load unknown"*) ok "a failing load reader prints 'load unknown', not an empty value" ;; *) bad "empty load: $out" ;; esac
+
+out=$(run 'printf "%s\n" "$ROWS"' GAUNTLET_STRAY_MIN_SECS=20 GAUNTLET_STRAY_MIN_CPU=1)
+case "$(line yes)" in *"3 processes"*) ok "GAUNTLET_STRAY_MIN_SECS lowers the age threshold" ;; *) bad "env age ignored: $out" ;; esac
+case "$(line zsh)" in *"pids 4444"*) ok "GAUNTLET_STRAY_MIN_CPU lowers the CPU threshold" ;; *) bad "env cpu ignored: $out" ;; esac
+
+out=$(run 'printf "%s\n" "$ROWS"' GAUNTLET_STRAY_MIN_SECS=1h GAUNTLET_STRAY_MIN_CPU=x)
+case "$out" in *zsh*|*"3 processes"*) bad "a non-numeric threshold changed the result: $out" ;; *"pids 82797"*) ok "a non-numeric threshold falls back to the default" ;; *) bad "fallback run lost the yes group: $out" ;; esac
+
+out=$(bash -ec ". '$LIB'; _sp_ps() { return 1; }; stray_procs_report; echo after" 2>/dev/null)
+[ "$out" = "after" ] && ok "a set -e caller is not aborted" || bad "set -e caller aborted: $out"
+
+# Wiring: the gauntlet reports before it starts the layers (the failure-path call and its place
+# above the failing: list are covered by test-gauntlet-failed-summary.sh). Text check only;
+# running the gauntlet from a gauntlet test would recurse.
+first=$(/usr/bin/grep -n -m1 '^stray_procs_report' "$GAUNTLET" | cut -d: -f1)
+layers=$(/usr/bin/grep -n -m1 '^run_hook_tests >' "$GAUNTLET" | cut -d: -f1)
+if [ -n "$first" ] && [ -n "$layers" ] && [ "$first" -lt "$layers" ]; then
+  ok "run-gauntlet.sh calls stray_procs_report before it starts the layers"
+else
+  bad "no stray_procs_report call before the layers start (call line '$first', layers line '$layers')"
+fi
+
+echo "stray-procs: $pass passed, $fail failed"
+[ "$fail" -eq 0 ]