Who wrote episode 31 in the series?
CREATE TABLE table_21831229_3 (written_by VARCHAR, no_in_series VARCHAR)
SELECT written_by FROM table_21831229_3 WHERE no_in_series = 31
### Context: CREATE TABLE table_21831229_3 (written_by VARCHAR, no_in_series VARCHAR) ### Question: Who wrote episode 31 in the series? ### Answer: SELECT written_by FROM table_21831229_3 WHERE no_in_series = 31