if the 2.09 million US viewers watched this episode, who was it written by
CREATE TABLE "table1_25084227_1" (
  "no" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "production_code" text,
  "u_s_viewers_in_millions" text
);
SELECT "written_by" FROM "table1_25084227_1" WHERE "u_s_viewers_in_millions"='2.09';