Who directed episode 21?
CREATE TABLE table_23958944_5 (directed_by VARCHAR, no_by_season VARCHAR)
SELECT directed_by FROM table_23958944_5 WHERE no_by_season = 21
### Context: CREATE TABLE table_23958944_5 (directed_by VARCHAR, no_by_season VARCHAR) ### Question: Who directed episode 21? ### Answer: SELECT directed_by FROM table_23958944_5 WHERE no_by_season = 21