CREATE TABLE table_18268826_1 (written_by VARCHAR2, us_viewers__million_ VARCHAR2)

Who's the writer of the episode seen by 3.25 million people in the US?
SELECT written_by FROM table_18268826_1 WHERE us_viewers__million_ = "3.25"
SELECT "written_by" FROM "table_18268826_1" WHERE "3.25" = "us_viewers__million_"