CREATE TABLE table_2370579_1 (directed_by VARCHAR2, written_by VARCHAR2)

Who directed the episode written by Tony O'Grady (pseudonym of brian clemens)?
SELECT directed_by FROM table_2370579_1 WHERE written_by = "Tony O'Grady (pseudonym of Brian Clemens)"
SELECT "directed_by" FROM "table_2370579_1" WHERE "Tony O'Grady (pseudonym of Brian Clemens)" = "written_by"