diff --git a/0027/SESSION-0027.0-TRANSCRIPT-2026-05-28T13-46--INPROGRESS.md b/0027/SESSION-0027.0-TRANSCRIPT-2026-05-28T13-46--INPROGRESS.md
new file mode 100644
index 0000000..7bdd374
--- /dev/null
+++ b/0027/SESSION-0027.0-TRANSCRIPT-2026-05-28T13-46--INPROGRESS.md
@@ -0,0 +1,15 @@
+# Session 0027.0 — Transcript
+
+> Date: 2026-05-28
+> Start: 2026-05-28T13-46 (PST implied)
+> Status: **PLACEHOLDER — claimed at session start; finalized at session end.**
+>
+> This file reserves session ID 0027. The driver replaces this body
+> with the full transcript before publishing, and renames the file to
+> its final SESSION-0027.0-TRANSCRIPT-2026-05-28T13-46--<end>.md form.
+
+---
+
+## Launch prompt
+
+_(launch prompt not captured at claim time)_
diff --git a/sessions.json b/sessions.json
index 0d8d945..e424ffa 100644
--- a/sessions.json
+++ b/sessions.json
@@ -64,5 +64,8 @@
   },
   "0026": {
     "title": ""
+  },
+  "0027": {
+    "title": ""
   }
 }