diff --git a/0050/SESSION-0050.0-TRANSCRIPT-2026-05-31T12-00--2026-05-31T12-00.md b/0050/SESSION-0050.0-TRANSCRIPT-2026-05-31T12-00--2026-05-31T12-00.md
new file mode 100644
index 0000000..36ce072
--- /dev/null
+++ b/0050/SESSION-0050.0-TRANSCRIPT-2026-05-31T12-00--2026-05-31T12-00.md
@@ -0,0 +1,23 @@
+# Session 0050.0 — Transcript
+
+> Date: 2026-05-31
+> Goal: _(none — accidental duplicate claim)_
+>
+> Outcome: **ABORTED. This session ID was claimed by accident.**
+
+---
+
+## Pre-session state
+
+Session 0049 ran `claim-session-id.sh` twice in a single tool batch (a
+sandboxed call that was assumed to have failed actually succeeded and
+claimed 0049; a follow-up call then claimed 0050). 0049 is the real
+session. This 0050 slot never did any work.
+
+## Why this exists
+
+Per SESSION-PROTOCOL.md §7, gaps are never reused and an unfinalized
+`--INPROGRESS` file reads as a live session. To avoid leaving a phantom
+live session in the shared registry, 0050 is finalized immediately as an
+aborted stub with start == end. No work was done under this ID; see
+SESSION-0049.0 for the actual session.
diff --git a/0050/SESSION-0050.0-TRANSCRIPT-2026-05-31T12-00--INPROGRESS.md b/0050/SESSION-0050.0-TRANSCRIPT-2026-05-31T12-00--INPROGRESS.md
deleted file mode 100644
index 670311e..0000000
--- a/0050/SESSION-0050.0-TRANSCRIPT-2026-05-31T12-00--INPROGRESS.md
+++ /dev/null
@@ -1,15 +0,0 @@
-# Session 0050.0 — Transcript
-
-> Date: 2026-05-31
-> Start: 2026-05-31T12-00 (PST implied)
-> Status: **PLACEHOLDER — claimed at session start; finalized at session end.**
->
-> This file reserves session ID 0050. The driver replaces this body
-> with the full transcript before publishing, and renames the file to
-> its final SESSION-0050.0-TRANSCRIPT-2026-05-31T12-00--<end>.md form.
-
----
-
-## Launch prompt
-
-_(launch prompt not captured at claim time)_