diff --git a/chainsyncer/session.py b/chainsyncer/session.py
index 5335c5a..d299f3a 100644
--- a/chainsyncer/session.py
+++ b/chainsyncer/session.py
@@ -23,6 +23,10 @@ class SyncSession:
         return self.item
 
 
+    def stop(self, item):
+        self.session_store.stop(item)
+
+
     def filter(self, conn, block, tx):
         self.session_store.connect()
         for fltr in self.filters:
diff --git a/chainsyncer/store/fs.py b/chainsyncer/store/fs.py
index 4739a42..8c5afcf 100644
--- a/chainsyncer/store/fs.py
+++ b/chainsyncer/store/fs.py
@@ -29,9 +29,8 @@ class SyncFsItem:
         self.sync_state = sync_state
         self.filter_state = filter_state
         self.state_key = str(offset)
-        match_state = self.sync_state.NEW
-        if started:
-            match_state = self.sync_state.SYNC
+
+        logg.debug('get key {}'.format(self.state_key))
         v = self.sync_state.get(self.state_key)
         self.cursor = int.from_bytes(v[:4], 'big')
         self.tx_cursor = int.from_bytes(v[4:], 'big')
@@ -43,7 +42,7 @@ class SyncFsItem:
         self.skip_filter = False
         if self.count == 0:
             self.skip_filter = True
-        else:
+        elif not started:
             self.filter_state.move(self.state_key, self.filter_state.from_name('RESET'))
 
 
@@ -123,7 +122,7 @@ class SyncFsItem:
             self.filter_state.set(self.state_key, self.filter_state.from_name('DONE'))
             return False
         return True
-        
+       
 
     def __str__(self):
         return 'syncitem offset {} target {} cursor {}'.format(self.offset, self.target, self.cursor)
@@ -161,6 +160,7 @@ class SyncFsStore:
 
         if create_path:
             self.__create_path(base_path, default_path, session_id=session_id)
+        self.session_id = os.path.basename(self.session_path)
 
         logg.info('session id {} resolved {} path {}'.format(session_id, self.session_id, self.session_path))
 
@@ -187,7 +187,6 @@ class SyncFsStore:
             session_id = str(uuid.uuid4())
         self.session_path = os.path.join(base_path, session_id)
         os.makedirs(self.session_path)
-        self.session_id = os.path.basename(self.session_path)
         
         if self.is_default:
             try:
@@ -222,7 +221,7 @@ class SyncFsStore:
             o = SyncFsItem(block_number, item_target, self.state, self.filter_state, started=True)
             self.items[block_number] = o
             self.item_keys.append(block_number)
-            logg.info('added {}'.format(o))
+            logg.info('added existing {}'.format(o))
 
         fp = os.path.join(self.session_path, str(target))
         if len(thresholds) == 0:
@@ -237,8 +236,6 @@ class SyncFsStore:
         f.close()
         self.target = int(v)
 
-        logg.debug('target {}'.format(self.target))
-
 
     def start(self, offset=0, target=-1):
         if self.started:
@@ -257,6 +254,7 @@ class SyncFsStore:
             o = SyncFsItem(block_number, target, self.state, self.filter_state)
             self.items[block_number] = o
             self.item_keys.append(block_number)
+            logg.debug('added first {}'.format(o))
         elif offset > 0:
             logg.warning('block number argument {} for start ignored for already initiated sync {}'.format(offset, self.session_id))
         self.started = True
@@ -264,13 +262,21 @@ class SyncFsStore:
         self.item_keys.sort()
 
 
-    def stop(self):
-#        if self.target == 0:
-#            block_number = self.height + 1
-#            block_number_bytes = block_number.to_bytes(4, 'big')
-#            block_number_bytes = block_number.to_bytes(4, 'big')
-#            self.state.put(str(block_number), block_number_bytes)
-        pass
+    def stop(self, item):
+        if item.target == -1:
+            state_bytes = sync_state_serialize(item.cursor, 0, item.cursor)
+            self.state.replace(str(item.offset), state_bytes)
+            self.filter_state.put(str(item.cursor))
+
+            SyncFsItem(item.offset, -1, self.state, self.filter_state)
+            logg.info('New sync state start at block number {} for next head sync backfill'.format(item.cursor))
+
+            self.state.move(item.state_key, self.state.DONE)
+
+            state_bytes = sync_state_serialize(item.cursor, 0, -1)
+            self.state.put(str(item.cursor), state_bytes)
+
+        logg.debug('item {}'.format(self.state.state(item.state_key)))
 
 
     def get(self, k):
@@ -291,3 +297,17 @@ class SyncFsStore:
 
     def disconnect(self):
         self.filter_state.disconnect()
+
+
+def sync_state_serialize(block_height, tx_index, block_target):
+    b = block_height.to_bytes(4, 'big')
+    b += tx_index.to_bytes(4, 'big')
+    b += block_target.to_bytes(4, 'big', signed=True)
+    return b
+
+
+def sync_state_deserialize(b):
+    block_height = int.from_bytes(b[:4], 'big')
+    tx_index = int.from_bytes(b[4:8], 'big')
+    block_target = int.from_bytes(b[8:], 'big', signed=True)
+    return (block_height, tx_index, block_target,)
diff --git a/tests/test_fs.py b/tests/test_fs.py
index 75e064c..976b0dd 100644
--- a/tests/test_fs.py
+++ b/tests/test_fs.py
@@ -188,5 +188,22 @@ class TestFs(unittest.TestCase):
             o.next(advance_block=True)
 
 
+    def test_sync_head_future(self):
+        store = SyncFsStore(self.path, session_id='foo')
+        session = SyncSession(store)
+
+        session.start()
+        logg.debug('list {} {} {}'.format(store.state.list(store.state.SYNC), store.state.list(store.state.DONE), store.state.list(store.state.NEW)))
+        o = session.get(0)
+        o.next(advance_block=True)
+        o.next(advance_block=True)
+        session.stop(o)
+
+        logg.debug('list {} {} {}'.format(store.state.list(store.state.SYNC), store.state.list(store.state.DONE), store.state.list(store.state.NEW)))
+        store = SyncFsStore(self.path, session_id='foo')
+        store.start()
+        o = store.get(2)
+
+
 if __name__ == '__main__':
     unittest.main()