diff --git a/.github/workflows/cloud-operate-relay-production-rehome-job.yml b/.github/workflows/cloud-operate-relay-production-rehome-job.yml
index a34552b898f..b16132d9ba5 100644
--- a/.github/workflows/cloud-operate-relay-production-rehome-job.yml
+++ b/.github/workflows/cloud-operate-relay-production-rehome-job.yml
@@ -320,7 +320,7 @@ jobs:
             echo '### Regional rehome control'
             jq -r '"- mode: `\(.mode)`\n- generation: `\(.control.generation)`\n- enabled: `\(.control.enabled)`"' \
               "${RUNNER_TEMP}/relay-rehome-control.json"
-            jq -r '"- active: `\(.active)`\n- awaiting receipt: `\(.awaitingReceipt)`\n- target registered: `\(.targetRegistered)`\n- completed (24h): `\(.completedLast24Hours)`\n- aborted (24h): `\(.abortedLast24Hours)`"' \
+            jq -r '"- active: `\(.active)`\n- awaiting receipt: `\(.awaitingReceipt)`\n- target registered: `\(.targetRegistered)`\n- completed (24h): `\(.completedLast24Hours)`\n- aborted (24h): `\(.abortedLast24Hours)`\n- host not arrived (24h): `\(.hostNotArrivedLast24Hours // "not reported")`\n- oldest active age (ms): `\(.oldestActiveAgeMs // "none")`"' \
               "${RUNNER_TEMP}/relay-rehome-inventory.json"
           } >> "${GITHUB_STEP_SUMMARY}"
 
diff --git a/cloud/apps/relay/src/regional-rehome-inventory-line-census.test.ts b/cloud/apps/relay/src/regional-rehome-inventory-line-census.test.ts
new file mode 100644
index 00000000000..6e0b00a263c
--- /dev/null
+++ b/cloud/apps/relay/src/regional-rehome-inventory-line-census.test.ts
@@ -0,0 +1,163 @@
+import { describe, expect, it } from 'vitest'
+import {
+  formatAssignmentInventorySnapshot,
+  type AssignmentInventorySnapshot
+} from './assignment-inventory-snapshot.js'
+
+// The enable workflow reads the director's rehome inventory line out of Cloud
+// Logging with a parser that lives in another language, in another package, and
+// is never exercised against the formatter that writes the line. When
+// `hostNotArrivedLast24Hours` shipped, the parser read a healthy line as no
+// evidence at all and the run failed closed, disabling the durable switch. This
+// test is the missing edge: the real formatter's output, through the real
+// parser, so a future field fails here instead of in an operator's run.
+
+type InventoryEvidence = {
+  active: number
+  awaitingReceipt: number
+  targetRegistered: number
+  completedLast24Hours: number
+  abortedLast24Hours: number
+  hostNotArrivedLast24Hours: number | null
+  oldestActiveAgeMs: number | null
+}
+
+// Imported through a computed URL on purpose: the script is plain ESM outside
+// this package's compile scope, so a static import would not resolve.
+async function loadParser(): Promise<(entries: unknown[], options: unknown) => InventoryEvidence> {
+  const source = new URL(
+    '../../../dev/scripts/relay-rehome-aggregate-evidence.mjs',
+    import.meta.url
+  ).href
+  const loaded: unknown = await import(/* @vite-ignore */ source)
+  if (!(loaded !== null && typeof loaded === 'object' && 'parseRegionalRehomeInventory' in loaded)) {
+    throw new Error('relay-rehome-aggregate-evidence.mjs no longer exports its parser')
+  }
+  const parse = loaded.parseRegionalRehomeInventory
+  if (typeof parse !== 'function') throw new Error('parseRegionalRehomeInventory is not callable')
+  return (entries, options) => readEvidence(parse(entries, options))
+}
+
+function readEvidence(value: unknown): InventoryEvidence {
+  if (value === null || typeof value !== 'object') throw new Error('parser returned no evidence')
+  const counts = ['active', 'awaitingReceipt', 'targetRegistered', 'completedLast24Hours', 'abortedLast24Hours'] as const
+  const evidence: Record<string, number | null> = {}
+  for (const key of [...counts, 'hostNotArrivedLast24Hours', 'oldestActiveAgeMs'] as const) {
+    if (!(key in value)) throw new Error(`parser dropped ${key}`)
+    const read: unknown = Reflect.get(value, key)
+    if (read !== null && typeof read !== 'number') throw new Error(`${key} is not a count`)
+    evidence[key] = read
+  }
+  for (const key of counts) {
+    if (evidence[key] === null) throw new Error(`${key} must be a number`)
+  }
+  return {
+    active: Number(evidence['active']),
+    awaitingReceipt: Number(evidence['awaitingReceipt']),
+    targetRegistered: Number(evidence['targetRegistered']),
+    completedLast24Hours: Number(evidence['completedLast24Hours']),
+    abortedLast24Hours: Number(evidence['abortedLast24Hours']),
+    hostNotArrivedLast24Hours: evidence['hostNotArrivedLast24Hours'] ?? null,
+    oldestActiveAgeMs: evidence['oldestActiveAgeMs'] ?? null
+  }
+}
+
+function snapshot(
+  regionalRehomes: AssignmentInventorySnapshot['regionalRehomes']
+): AssignmentInventorySnapshot {
+  return {
+    cells: [],
+    activityLeases: { total: 0, expired: 0, requestUnits: 0 },
+    connectionReservations: { outstanding: 0, lateArrivalDebt: 0 },
+    regionalRehomes
+  }
+}
+
+function inventoryLine(snapshotValue: AssignmentInventorySnapshot): string {
+  const line = formatAssignmentInventorySnapshot(snapshotValue).find((candidate) =>
+    candidate.startsWith('[orca-relay] regional rehome inventory ')
+  )
+  if (!line) throw new Error('the formatter no longer emits a rehome inventory line')
+  return line
+}
+
+describe('regional rehome inventory line census', () => {
+  it('parses what the director actually prints, field for field', async () => {
+    const parse = await loadParser()
+    const regionalRehomes = {
+      active: 3,
+      awaitingReceipt: 1,
+      targetRegistered: 2,
+      completedLast24Hours: 41,
+      abortedLast24Hours: 12,
+      hostNotArrivedLast24Hours: 5,
+      oldestActiveAgeMs: 77_731_209
+    }
+    const now = Date.parse('2026-09-20T12:00:00Z')
+
+    const evidence = parse(
+      [{ timestamp: '2026-09-20T11:59:00Z', textPayload: inventoryLine(snapshot(regionalRehomes)) }],
+      { now, maxAgeMs: 5 * 60_000 }
+    )
+
+    expect(evidence).toEqual({ ...regionalRehomes })
+  })
+
+  it('parses the line an idle fleet prints, with no oldest active age', async () => {
+    const parse = await loadParser()
+    const now = Date.parse('2026-09-20T12:00:00Z')
+
+    const evidence = parse(
+      [
+        {
+          timestamp: '2026-09-20T11:59:00Z',
+          textPayload: inventoryLine(
+            snapshot({
+              active: 0,
+              awaitingReceipt: 0,
+              targetRegistered: 0,
+              completedLast24Hours: 0,
+              abortedLast24Hours: 0,
+              hostNotArrivedLast24Hours: 0,
+              oldestActiveAgeMs: null
+            })
+          )
+        }
+      ],
+      { now, maxAgeMs: 5 * 60_000 }
+    )
+
+    expect(evidence.oldestActiveAgeMs).toBeNull()
+    expect(evidence.hostNotArrivedLast24Hours).toBe(0)
+  })
+
+  it('covers every counter the formatter puts on the line', async () => {
+    const parse = await loadParser()
+    // A field the parser ignores is a field the operator never sees, so the
+    // census fails when the formatter gains one and this test is not updated.
+    const line = inventoryLine(
+      snapshot({
+        active: 1,
+        awaitingReceipt: 1,
+        targetRegistered: 1,
+        completedLast24Hours: 1,
+        abortedLast24Hours: 1,
+        hostNotArrivedLast24Hours: 1,
+        oldestActiveAgeMs: 1
+      })
+    )
+    const printed = line
+      .slice('[orca-relay] regional rehome inventory '.length)
+      .split(' ')
+      .map((field) => field.split('=')[0])
+
+    const surfaced = Object.keys(
+      parse([{ timestamp: '2026-09-20T11:59:00Z', textPayload: line }], {
+        now: Date.parse('2026-09-20T12:00:00Z'),
+        maxAgeMs: 5 * 60_000
+      })
+    )
+
+    expect([...printed].sort()).toEqual([...surfaced].sort())
+  })
+})
diff --git a/cloud/dev/scripts/relay-rehome-aggregate-evidence.mjs b/cloud/dev/scripts/relay-rehome-aggregate-evidence.mjs
index 82bc2fb522a..a0563ffa94a 100644
--- a/cloud/dev/scripts/relay-rehome-aggregate-evidence.mjs
+++ b/cloud/dev/scripts/relay-rehome-aggregate-evidence.mjs
@@ -1,6 +1,24 @@
 import { pathToFileURL } from 'node:url'
 
-const INVENTORY = /^\[orca-relay\] regional rehome inventory active=(\d+) awaitingReceipt=(\d+) targetRegistered=(\d+) completedLast24Hours=(\d+) abortedLast24Hours=(\d+) oldestActiveAgeMs=(none|\d+)$/
+const INVENTORY_PREFIX = '[orca-relay] regional rehome inventory '
+// A counters line, so every field is a bare name and a non-negative integer or
+// `none`. Pinning the whole line instead is what broke the enable workflow when
+// `hostNotArrivedLast24Hours` shipped: the director grew a field and the parser
+// read a healthy line as no evidence at all. Tolerating extra fields is safe
+// only because the value shape stays fenced — `hostId=someone` is still not a
+// counter, so an identity-bearing lookalike cannot slip through as an extra.
+const FIELD = /^([A-Za-z][A-Za-z0-9]*)=(none|\d{1,15})$/
+// `oldestActiveAgeMs` is the one required field the director can report as
+// `none`; a count that reads `none` is a line this parser does not recognise,
+// not evidence worth failing the run over.
+const REQUIRED_COUNTS = [
+  'active',
+  'awaitingReceipt',
+  'targetRegistered',
+  'completedLast24Hours',
+  'abortedLast24Hours'
+]
+const REQUIRED_FIELDS = [...REQUIRED_COUNTS, 'oldestActiveAgeMs']
 
 function count(value, name) {
   const parsed = Number(value)
@@ -8,20 +26,43 @@ function count(value, name) {
   return parsed
 }
 
+// Returns the field map, or null for anything that is not this line.
+export function readRegionalRehomeInventoryFields(textPayload) {
+  if (typeof textPayload !== 'string' || !textPayload.startsWith(INVENTORY_PREFIX)) return null
+  const fields = new Map()
+  for (const token of textPayload.slice(INVENTORY_PREFIX.length).split(' ')) {
+    const field = FIELD.exec(token)
+    if (!field || fields.has(field[1])) return null
+    fields.set(field[1], field[2])
+  }
+  if (!REQUIRED_FIELDS.every((name) => fields.has(name))) return null
+  if (REQUIRED_COUNTS.some((name) => fields.get(name) === 'none')) return null
+  return fields
+}
+
+// Absent is not zero: a director on an older image emits no such field, and
+// reporting 0 would read as "no leaks" rather than "not measured".
+function optionalCount(fields, name) {
+  const value = fields.get(name)
+  if (value === undefined || value === 'none') return null
+  return count(value, name)
+}
+
 export function parseRegionalRehomeInventory(entries, options = {}) {
   if (!Array.isArray(entries)) throw new Error('logging response must be an array')
   const parsed = entries.flatMap((entry) => {
-    const match = INVENTORY.exec(entry?.textPayload ?? '')
+    const fields = readRegionalRehomeInventoryFields(entry?.textPayload ?? '')
     const timestamp = Date.parse(entry?.timestamp ?? '')
-    if (!match || !Number.isFinite(timestamp)) return []
+    if (!fields || !Number.isFinite(timestamp)) return []
     return [{
       timestamp,
-      active: count(match[1], 'active'),
-      awaitingReceipt: count(match[2], 'awaiting receipt'),
-      targetRegistered: count(match[3], 'target registered'),
-      completedLast24Hours: count(match[4], 'completed'),
-      abortedLast24Hours: count(match[5], 'aborted'),
-      oldestActiveAgeMs: match[6] === 'none' ? null : count(match[6], 'oldest active age')
+      active: count(fields.get('active'), 'active'),
+      awaitingReceipt: count(fields.get('awaitingReceipt'), 'awaiting receipt'),
+      targetRegistered: count(fields.get('targetRegistered'), 'target registered'),
+      completedLast24Hours: count(fields.get('completedLast24Hours'), 'completed'),
+      abortedLast24Hours: count(fields.get('abortedLast24Hours'), 'aborted'),
+      hostNotArrivedLast24Hours: optionalCount(fields, 'hostNotArrivedLast24Hours'),
+      oldestActiveAgeMs: optionalCount(fields, 'oldestActiveAgeMs')
     }]
   }).sort((left, right) => right.timestamp - left.timestamp)
   if (parsed.length === 0) throw new Error('no aggregate regional rehome inventory evidence')
diff --git a/cloud/dev/scripts/relay-rehome-aggregate-evidence.test.mjs b/cloud/dev/scripts/relay-rehome-aggregate-evidence.test.mjs
index 2ce2627fb93..e85c4d5606d 100644
--- a/cloud/dev/scripts/relay-rehome-aggregate-evidence.test.mjs
+++ b/cloud/dev/scripts/relay-rehome-aggregate-evidence.test.mjs
@@ -1,6 +1,7 @@
 import assert from 'node:assert/strict'
 import { test } from 'node:test'
 import { parseRegionalRehomeInventory } from './relay-rehome-aggregate-evidence.mjs'
+import { readRelayWorkflow } from './relay-repository.mjs'
 
 const now = Date.parse('2026-08-14T12:00:00Z')
 
@@ -22,10 +23,38 @@ test('selects the newest fresh aggregate-only regional rehome inventory', () =>
     targetRegistered: 1,
     completedLast24Hours: 9,
     abortedLast24Hours: 0,
+    hostNotArrivedLast24Hours: null,
     oldestActiveAgeMs: 30_000
   })
 })
 
+test('reads a line the director grew a field on, wherever the field sits', () => {
+  const result = parseRegionalRehomeInventory([{
+    timestamp: '2026-08-14T11:58:00Z',
+    textPayload:
+      '[orca-relay] regional rehome inventory hostNotArrivedLast24Hours=4 active=2' +
+      ' awaitingReceipt=1 targetRegistered=1 completedLast24Hours=9 abortedLast24Hours=7' +
+      ' oldestActiveAgeMs=30000 someFieldFromALaterRelease=11'
+  }], { now, maxAgeMs: 5 * 60_000 })
+  assert.equal(result.hostNotArrivedLast24Hours, 4)
+  assert.equal(result.abortedLast24Hours, 7)
+  assert.equal(result.oldestActiveAgeMs, 30_000)
+})
+
+test('reports an unmeasured host-not-arrived count as absent, not as zero', () => {
+  const [withField, withoutField] = ['4', null].map((value) =>
+    parseRegionalRehomeInventory([{
+      timestamp: '2026-08-14T11:58:00Z',
+      textPayload:
+        '[orca-relay] regional rehome inventory active=0 awaitingReceipt=0 targetRegistered=0' +
+        ' completedLast24Hours=0 abortedLast24Hours=0 oldestActiveAgeMs=none' +
+        (value === null ? '' : ` hostNotArrivedLast24Hours=${value}`)
+    }], { now, maxAgeMs: 5 * 60_000 })
+  )
+  assert.equal(withField.hostNotArrivedLast24Hours, 4)
+  assert.equal(withoutField.hostNotArrivedLast24Hours, null)
+})
+
 test('rejects stale, malformed, and identity-bearing lookalikes', () => {
   assert.throws(() => parseRegionalRehomeInventory([{
     timestamp: '2026-08-14T11:00:00Z',
@@ -36,3 +65,71 @@ test('rejects stale, malformed, and identity-bearing lookalikes', () => {
     textPayload: '[orca-relay] regional rehome inventory active=0 hostId=secret'
   }], { now }), /no aggregate/)
 })
+
+test('keeps out an identity-bearing field riding along on a complete line', () => {
+  const complete =
+    '[orca-relay] regional rehome inventory active=0 awaitingReceipt=0 targetRegistered=0' +
+    ' completedLast24Hours=0 abortedLast24Hours=0 oldestActiveAgeMs=none'
+  for (const extra of [' hostId=secret', ' userId=someone@example.test', ' note=a b']) {
+    assert.throws(
+      () => parseRegionalRehomeInventory(
+        [{ timestamp: '2026-08-14T11:59:00Z', textPayload: complete + extra }],
+        { now }
+      ),
+      /no aggregate/,
+      extra
+    )
+  }
+})
+
+test('refuses a line missing a required field, or repeating one', () => {
+  const missing =
+    '[orca-relay] regional rehome inventory active=0 awaitingReceipt=0 targetRegistered=0' +
+    ' completedLast24Hours=0 oldestActiveAgeMs=none'
+  assert.throws(
+    () => parseRegionalRehomeInventory(
+      [{ timestamp: '2026-08-14T11:59:00Z', textPayload: missing }],
+      { now }
+    ),
+    /no aggregate/
+  )
+  assert.throws(
+    () => parseRegionalRehomeInventory(
+      [{ timestamp: '2026-08-14T11:59:00Z', textPayload: `${missing} abortedLast24Hours=0 abortedLast24Hours=1` }],
+      { now }
+    ),
+    /no aggregate/
+  )
+  assert.throws(
+    () => parseRegionalRehomeInventory(
+      [{
+        timestamp: '2026-08-14T11:59:00Z',
+        textPayload: missing.replace('active=0', 'active=none') + ' abortedLast24Hours=0'
+      }],
+      { now }
+    ),
+    /no aggregate/
+  )
+})
+
+// The third edge of the chain the enable workflow depends on. The formatter is
+// pinned against this parser in the relay package's inventory-line census; this
+// pins the parser against the summary an operator reads, so a field that
+// reaches the evidence JSON and stops there fails here.
+test('publishes every parsed counter in the operator step summary', () => {
+  const job = readRelayWorkflow('operate-relay-production-rehome-job.yml')
+  // The jq program and the file it reads sit on separate continuation lines, so
+  // match the whole render rather than one line of it.
+  const summary = /jq -r '([^']*)' \\\n\s*"\$\{RUNNER_TEMP\}\/relay-rehome-inventory\.json"/.exec(job)?.[1]
+  assert.ok(summary, 'the rehome job no longer renders the inventory evidence')
+  const evidence = parseRegionalRehomeInventory([{
+    timestamp: '2026-08-14T11:58:00Z',
+    textPayload:
+      '[orca-relay] regional rehome inventory active=0 awaitingReceipt=0 targetRegistered=0' +
+      ' completedLast24Hours=0 abortedLast24Hours=0 hostNotArrivedLast24Hours=0 oldestActiveAgeMs=none'
+  }], { now, maxAgeMs: 5 * 60_000 })
+  for (const key of Object.keys(evidence)) {
+    if (key === 'timestamp') continue
+    assert.ok(summary.includes(`.${key}`), `${key} is missing from the step summary`)
+  }
+})