diff --git a/src/hanoidb_level.erl b/src/hanoidb_level.erl
index 1d52a0f..40116da 100644
--- a/src/hanoidb_level.erl
+++ b/src/hanoidb_level.erl
@@ -533,6 +533,19 @@ main_loop(State = #state{ next=Next }) ->
         %% The outcome of merging resulted in a file with less than
         %% level #entries, so we keep it at this level
         %%
+        ?CAST(_From,{merge_done, 0, OutFileName}) ->
+            ok = file:delete(OutFileName),
+            {ok, State2} = close_and_delete_a_and_b(State),
+            case State#state.c of
+                undefined ->
+                    main_loop(State2#state{ merge_pid=undefined });
+                CFile ->
+                    ok = hanoidb_reader:close(CFile),
+                    ok = file:rename(filename("C", State2), filename("A", State2)),
+                    {ok, AFile} = hanoidb_reader:open(filename("A", State2), [random|State#state.opts]),
+                    main_loop(State2#state{ a = AFile, c = undefined, merge_pid=undefined })
+            end;
+
         ?CAST(_From,{merge_done, Count, OutFileName}) when Count =< ?BTREE_SIZE(State#state.level) ->
 
             ?log("merge_done, out:~w~n -> self", [Count]),
@@ -547,16 +560,18 @@ main_loop(State = #state{ next=Next }) ->
             % then, rename M to A, and open it
             AFileName = filename("A",State2),
             ok = file:rename(MFileName, AFileName),
-            {ok, BT} = hanoidb_reader:open(AFileName, [random|State#state.opts]),
+            {ok, AFile} = hanoidb_reader:open(AFileName, [random|State#state.opts]),
 
             % iff there is a C file, then move it to B position
             % TODO: consider recovery for this
             case State#state.c of
                 undefined ->
-                    main_loop(State2#state{ a=BT, b=undefined, merge_pid=undefined });
-                TreeFile ->
-                    file:rename(filename("C",State2), filename("B", State2)),
-                    check_begin_merge_then_loop(State2#state{ a=BT, b=TreeFile, c=undefined,
+                    main_loop(State2#state{ a=AFile, b=undefined, merge_pid=undefined });
+                CFile ->
+                    ok = hanoidb_reader:close(CFile),
+                    ok = file:rename(filename("C", State2), filename("B", State2)),
+                    {ok, BFile} = hanoidb_reader:open(filename("B", State2), [random|State#state.opts]),
+                    check_begin_merge_then_loop(State2#state{ a=AFile, b=BFile, c=undefined,
                                                               merge_pid=undefined })
             end;
 
diff --git a/src/hanoidb_writer.erl b/src/hanoidb_writer.erl
index 5a60d19..510f315 100644
--- a/src/hanoidb_writer.erl
+++ b/src/hanoidb_writer.erl
@@ -150,13 +150,17 @@ code_change(_OldVsn, State, _Extra) ->
 
 %%%%% INTERNAL FUNCTIONS
 
-serialize(#state{ bloom=Bloom, index_file=File }=State) ->
 %    io:format("serializing ~p @ ~p~n", [State#state.name,
 %                                        State#state.index_file_pos]),
+serialize(#state{ bloom=Bloom, index_file=File, index_file_pos=Position }=State) ->
 
     %% assert that we're on track
-    Position = State#state.index_file_pos,
-    {ok, Position} = file:position(File, cur),
+    case file:position(File, {eof, 0}) of
+        {ok, Position} ->
+            ok;
+        {ok, WrongPosition} ->
+            exit({bad_position, Position, WrongPosition})
+    end,
 
     ok = file:close(File),
     erlang:term_to_binary( { State#state{ index_file=closed }, ebloom:serialize(Bloom) } ).
@@ -183,16 +187,25 @@ flush_nodes(#state{ nodes=[], last_node_pos=LastNodePos, last_node_size=_LastNod
     Bloom = zlib:zip(ebloom:serialize(Ref)),
     BloomSize = byte_size(Bloom),
 
-    Trailer = << 0:32, Bloom/binary, BloomSize:32/unsigned,  LastNodePos:64/unsigned >>,
     IdxFile = State#state.index_file,
 
+    if LastNodePos =:= undefined ->
+            %% store contains no entries!
+            ok = file:write(IdxFile, <<0:32,0:16>>),
+            RootPos = ?FIRST_BLOCK_POS;
+       true ->
+            RootPos = LastNodePos
+    end,
+
+    Trailer = << 0:32, Bloom/binary, BloomSize:32/unsigned,  RootPos:64/unsigned >>,
+
     ok = file:write(IdxFile, Trailer),
 
     ok = file:datasync(IdxFile),
 
     ok = file:close(IdxFile),
 
-    {ok, State#state{ index_file=undefined }};
+    {ok, State#state{ index_file=undefined, index_file_pos=undefined }};
 
 %% stack consists of one node with one {pos,len} member.  Just ignore this node.
 flush_nodes(State=#state{ nodes=[#node{level=N, members=[{_,{Pos,_Len}}]}], last_node_pos=Pos }) when N>0 ->