I'm assuming that helpers will know the structure of the two crosswords by now. If that is wrong please let me know.
Both 17 downs would help.
The (joint) clue (I'm not sure of the division) is Novel compiler having to get rid of the summer in France. Or which one has the extra letter. Both answers are 7 letters.
I think the RH answer is DEPLETE, in which case the added letter could be P. For the LH I have ?R?A???
All help appreciated.