diff --git a/scripts-dev/complement.sh b/scripts-dev/complement.sh
index 0b00e2f8ce..1e3bf357f7 100755
--- a/scripts-dev/complement.sh
+++ b/scripts-dev/complement.sh
@@ -65,4 +65,4 @@ if [[ -n "$1" ]]; then
 fi
 
 # Run the tests!
-go test -v -tags synapse_blacklist,msc2946,msc3083,msc2716 -count=1 $EXTRA_COMPLEMENT_ARGS ./tests -run TestBackfillingHistory/parallel/Backfilled_historical_events_resolve_with_proper_state_in_correct_order
+go test -v -tags synapse_blacklist,msc2946,msc3083,msc2716 -count=1 $EXTRA_COMPLEMENT_ARGS ./tests -run TestBackfillingHistory/parallel/Historical_messages_are_visible_when_joining_on_federated_server
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index e0ab9eca48..ecf401f938 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -1057,7 +1057,9 @@ class FederationHandler(BaseHandler):
         self, room_id: str, current_depth: int, limit: int
     ) -> bool:
         extremities = await self.store.get_oldest_events_with_depth_in_room(room_id)
-        logger.info("_maybe_backfill_inner extremities=%s", extremities)
+        logger.info(
+            "_maybe_backfill_inner extremities(%d)=%s", len(extremities), extremities
+        )
 
         if not extremities:
             logger.debug("Not backfilling as no extremeties found.")
diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py
index 522f1f364e..eda940c31b 100644
--- a/synapse/storage/databases/main/event_federation.py
+++ b/synapse/storage/databases/main/event_federation.py
@@ -657,20 +657,42 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, SQLBas
         )
 
     def get_oldest_events_with_depth_in_room_txn(self, txn, room_id):
+        # sql = (
+        #     "SELECT b.event_id, MAX(e.depth) FROM events as e"
+        #     " INNER JOIN event_edges as g"
+        #     " ON g.event_id = e.event_id"
+        #     " INNER JOIN event_backward_extremities as b"
+        #     " ON g.prev_event_id = b.event_id"
+        #     # TODO
+        #     # " INNER JOIN insertion_event_extremeties as i"
+        #     # " ON g.event_id = i.insertion_prev_event_id"
+        #     " WHERE b.room_id = ? AND g.is_state is ?"
+        #     " GROUP BY b.event_id"
+        # )
+        # txn.execute(sql, (room_id, False))
+
+        sqlAsdf = "SELECT * FROM insertion_event_extremeties as i"
+        txn.execute(sqlAsdf)
+        logger.info("wfeafewawafeawg %s", dict(txn))
+
+        sqlAsdf = "SELECT * FROM insertion_event_extremeties as i WHERE i.room_id = ?"
+        txn.execute(sqlAsdf, (room_id,))
+        logger.info("awfeawefw %s", dict(txn))
+
         sql = (
-            "SELECT b.event_id, MAX(e.depth) FROM events as e"
-            " INNER JOIN event_edges as g"
-            " ON g.event_id = e.event_id"
-            " INNER JOIN event_backward_extremities as b"
-            " ON g.prev_event_id = b.event_id"
+            "SELECT i.insertion_event_id, MAX(e.depth) FROM events as e"
+            # " INNER JOIN event_edges as g"
+            # " ON g.event_id = e.event_id"
+            # " INNER JOIN event_backward_extremities as b"
+            # " ON g.prev_event_id = b.event_id"
             # TODO
-            # " INNER JOIN insertion_event_extremeties as i"
-            # " ON g.event_id = i.insertion_prev_event_id"
-            " WHERE b.room_id = ? AND g.is_state is ?"
-            " GROUP BY b.event_id"
+            " INNER JOIN insertion_event_extremeties as i"
+            " ON e.event_id = i.insertion_prev_event_id"
+            " WHERE i.room_id = ?"
+            " GROUP BY i.insertion_event_id"
         )
 
-        txn.execute(sql, (room_id, False))
+        txn.execute(sql, (room_id,))
 
         return dict(txn)
 
@@ -923,6 +945,7 @@ class EventFederationWorkerStore(EventsWorkerStore, SignatureWorkerStore, SQLBas
         # We want to make sure that we do a breadth-first, "depth" ordered
         # search.
 
+        # TODO
         query = (
             "SELECT depth, prev_event_id FROM event_edges"
             " INNER JOIN events"