diff --git a/backend/shonar/api/v1/recordings.py b/backend/shonar/api/v1/recordings.py
index 0ac74c3..dccf852 100644
--- a/backend/shonar/api/v1/recordings.py
+++ b/backend/shonar/api/v1/recordings.py
@@ -7,6 +7,7 @@ return 404 (no existence leaks). Storage keys are never exposed.
 from __future__ import annotations
 
 import contextlib
+import logging
 import uuid
 from datetime import datetime
 
@@ -42,6 +43,7 @@ from shonar.db.models import (
 from shonar.services import uploads as up
 
 router = APIRouter(tags=["uploads", "recordings"])
+logger = logging.getLogger("shonar.recordings")
 
 
 async def _recording_out(session, rec: Recording) -> RecordingOut:  # noqa: ANN001
@@ -400,6 +402,8 @@ async def reprocess_recording(
         JobStatus.running,
     ):
         raise HTTPException(409, "That stage is already running.")
+    prior_tone = existing.tone if existing is not None else None
+    prior_status = existing.status.value if existing is not None else "new"
     if existing is None:
         session.add(ProcessingJob(recording_id=rec.id, job_type=job_type,
                                   tone=tone))
@@ -414,6 +418,15 @@ async def reprocess_recording(
         # Tone rides the job row (the queue carries only ids): a plain
         # re-summarize must clear a previous tone, not inherit it.
         existing.tone = tone
+    # TRACE (logging only): one line per click. rid joins this line to the
+    # worker's start/done lines; prior_tone/prior_status expose rapid double
+    # clicks overwriting a queued tone before pickup.
+    logger.info(
+        "TRACE reprocess rid=%s rec=%s job=%s tone=%r prior_tone=%r "
+        "prior_status=%s",
+        proc.trace_request(rec.id, job_type, tone),
+        rec.id, job_type, tone, prior_tone, prior_status,
+    )
     if job_type is JT.transcribe:
         if model is not None:
             # A re-transcribe may switch models; the saved per-recording
diff --git a/backend/shonar/services/processing.py b/backend/shonar/services/processing.py
index bebfef7..35da1af 100644
--- a/backend/shonar/services/processing.py
+++ b/backend/shonar/services/processing.py
@@ -49,6 +49,27 @@ from shonar.storage import get_storage
 
 logger = logging.getLogger("shonar.processing")
 
+# --- tone/request-integrity trace (pure logging; remove when the
+# tone-mismatch investigation closes) ---------------------------------------
+# POST /reprocess mints an rid per request and stashes it here keyed by
+# (recording, job); the worker and store_summary read it back so all the
+# lines for one click share the same rid= and can be grepped together.
+# Single-process inline queue makes this safe; it carries no behavior.
+_trace_rid: dict = {}
+
+
+def trace_request(recording_id, job_type, tone):
+    """Called from POST /reprocess. Returns the rid for the request log."""
+    rid = uuid.uuid4().hex[:8]
+    _trace_rid[(str(recording_id), str(job_type))] = rid
+    logger.info("TRACE reprocess rid=%s rec=%s job=%s tone=%r",
+                rid, recording_id, job_type, tone)
+    return rid
+
+
+def trace_peek(recording_id, job_type):
+    return _trace_rid.get((str(recording_id), str(job_type)), "-")
+
 
 def _accepts_on_progress(provider) -> bool:
     """True when the provider's transcribe() accepts on_progress=."""
@@ -109,6 +130,10 @@ def _async_progress_writer(job_id):
         if int(pct) == last:
             return
         last = int(pct)
+        # TRACE (logging only): every distinct progress value the provider
+        # emits, with wall time — proves whether/when the 99 is emitted and
+        # written vs. the UI only ever showing 0%.
+        logger.info("TRACE progress job=%s pct=%s", job_id, pct)
 
         async def _write() -> None:
             from sqlalchemy import update
@@ -481,6 +506,13 @@ async def run_summarize(ctx: dict, recording_id: str) -> None:
         job.stage = "summarizing"
         rec.processing_status = ProcessingStatus.processing
         await session.commit()  # visible before the long LLM call
+        # TRACE (logging only): the tone the worker actually reads from the
+        # row NOW — differs from the reprocess line's tone if a later click
+        # overwrote it before pickup.
+        logger.info("TRACE summarize-start rid=%s job=%s rec=%s type=%s "
+                    "tone=%r attempt=%s",
+                    trace_peek(rec.id, job.job_type), job.id, rec.id,
+                    job.job_type, job.tone, job.attempt)
         fallback_note: str | None = None
         result_provider = provider.name  # overwritten only on the rescue path
         try:
@@ -585,6 +617,12 @@ async def store_summary(
     model: str,
     tone: str | None = None,
 ) -> None:
+    # TRACE (logging only): the tone arriving at storage. Compare with the
+    # summarize-start line's tone for the same rid: a mismatch here means
+    # the value changed between worker pickup and the DB write.
+    logger.info("TRACE store_summary rid=%s rec=%s tone=%r provider=%s",
+                trace_peek(rec.id, "summarize"), rec.id, tone,
+                provider_name)
     existing = (
         await session.scalars(
             select(Summary)