anchor.diff:                      Clock
               end,
   
  -            {LocalClock,
  -                {forward_message, Name, Channel, Clock, PartitionKey, ServerRef, Message, Options}};
  +            {LocalClock, Message};
           CausalLabel ->
  -            %% Get causality assignment and message buffer.
  -            {ok, LocalClock0, CausalMessage} = partisan_causality_backend:emit(CausalLabel, Name, ServerRef, Message),
  -
  -            %% Wrap the clock wih a scope.
  -            %% TODO: Maybe do this wrapping inside of the causality backend.
  -            LocalClock = {CausalLabel, LocalClock0},
  -
  -            {LocalClock,
  -                {forward_message, Name, Channel, LocalClock, PartitionKey, ServerRef, CausalMessage, Options}}
  +            case Clock of 
  +                %% First time through.
  +                undefined ->
  +                    %% We don't have a clock yet, get one using the causality backend.
  +                    {ok, LocalClock0, CausalMessage} = partisan_causality_backend:emit(CausalLabel, Name, ServerRef, Message),
  +
  +                    %% Wrap the clock wih a scope.
  +                    %% TODO: Maybe do this wrapping inside of the causality backend.
  +                    LocalClock = {CausalLabel, LocalClock0},
  +
  +                    %% Return clock and wrapped message.
  +                    {LocalClock, CausalMessage};
  +                %% Retransmission.
  +                _ ->
  +                    %% Get the clock and message we used last time.
  +                    {ok, LocalClock, CausalMessage} = partisan_causality_backend:reemit(CausalLabel, Clock),
  +
  +                    %% Return clock and wrapped message.
  +                    {LocalClock, CausalMessage}
  +            end
       end,
   
       case Message of
  
positive.code:             end,
  
              %% Fire post-interposition functions.
              PostFoldFunUndefined = fun(_Name, PostInterpositionFun, ok) ->
                  PostInterpositionFun({forward_message, Name, OriginalMessage}, {forward_message, Name, Message}),
                  ok
              end,
              dict:fold(PostFoldFunUndefined, ok, PostInterpositionFuns),
  
              lager:info("~p: Message after send interposition is: ~p", [node(), Message]),
  
              case From of 
                  undefined ->
  
negative.code:     CausalLabel = proplists:get_value(causal_label, Options, undefined),
  
      %% Use local information for message unless it's a causal message.
      {MessageClock, FullMessage} = case CausalLabel of
          undefined ->
              %% Generate a message clock or use the provided clock.
              LocalClock = case Clock of
  