diff --git a/BURNIN.md b/BURNIN.md
index 0cf27b9..50cbad0 100644
--- a/BURNIN.md
+++ b/BURNIN.md
@@ -2691,3 +2691,72 @@ the fix.
 because `omitempty` does not omit a zero `time.Time`. The worker parses it back
 to a zero value and `watchHandoff` starts the clock, so behaviour is correct.
 It is the same marshalling trap the operator console hit.
+
+## Run 18, 2026-08-29: the implement-successor rung, proven
+
+Task `06G4VF5HZW7Q4JBM3TTY7W1Y64` on `c587f2c`, a five-phase plan whose phases
+are ten named checks rather than one refactor. Volume of mechanical work is
+what keeps the implement phase open; phase count does not.
+
+### The rotation
+
+```text
+13:43:10  implement session launched
+13:43:44  phase-1 verified
+13:44:04  phase-2 verified
+13:44:35  handoff requested, reason=milestone, delivered by watchHandoff's resend
+13:45:25  TaskLeaseRenewed
+13:46:51  TaskReleased   handoff_ref 0b4fae6f705a  anchor 8ea3c7d1ae8f
+13:46:51  TaskLeased     successor, same harness
+13:46:55  TaskPickupValidated
+13:47:06  TaskLaunchAcknowledged, still in implement
+```
+
+The lever was the worker state file, backdated past `handoffRetryAfter` so the
+request went out on the next tick. Under `c587f2c` that lever now produces a
+real prompt: the flag alone used to sit there unasked, which is how run 16
+ended in a silent expiry.
+
+### What the successor was given
+
+From `.orchestra/launch.md`, written at 13:47:05:
+
+```text
+## Current phase
+implement: Implement the accepted plan below. Verify as you go.
+
+## Verified git state
+- head: 8ea3c7d1ae8fd960897344694645117adbd8ee82
+- uncommitted changes: false
+
+## Current human decisions
+None recorded. Work from the goal and acceptance above.
+
+## Plan progress
+Orchestra established this by running the plan's own verification. You cannot
+write it.
+- phase-1 (...): automated checks passed at d3acd4989a20, stale because the
+  tree is now at 8ea3c7d1ae8f, waiting for the human to confirm the manual steps
+- phase-2 (...): automated checks passed at d3acd4989a20, stale because the
+  tree is now at 8ea3c7d1ae8f, waiting for the human to confirm the manual steps
+- phase-3 (Checks 7 to 8): not started
+- phase-4 (...): not started
+- phase-5 (...): not started
+```
+
+Everything the rung asked for is there: the complete accepted plan with all
+five phases, their files, changes and verification; the phases already
+verified; the first unfinished phase; and the current human authority. The
+launch context also carries the accepted research and its dead ends.
+
+**SHA staleness renders itself.** Neither phase is reported as simply passed.
+Each says the checks passed at `d3acd4989a20` and are stale because the tree
+has moved to `8ea3c7d1ae8f`. That is half of the manual-verification rung
+observed without being asked for.
+
+### The lever still loses a race, sometimes
+
+`systemctl restart` alone leaves a five-second window in which the running
+worker's tick save can clobber the edit. It clobbered run 17's attempt and
+survived run 18's. Stop, edit, start is the reliable sequence, and it needs
+`systemctl stop` and `start` in the unattended sudo rule.