Who directed the episode seen by 3.93 million people in the US?
CREATE TABLE table_18268826_1 (directed_by VARCHAR, us_viewers__million_ VARCHAR)
SELECT directed_by FROM table_18268826_1 WHERE us_viewers__million_ = "3.93"
### Context: CREATE TABLE table_18268826_1 (directed_by VARCHAR, us_viewers__million_ VARCHAR) ### Question: Who directed the episode seen by 3.93 million people in the US? ### Answer: SELECT directed_by FROM table_18268826_1 WHERE us_viewers__million_ = "3.93"