Who directed the episode with UK viewership of 6.09 million?
CREATE TABLE "table1_29063233_1" (
  "no_overall" real,
  "no_for_series" real,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "uk_viewers_million" text
);
SELECT "directed_by" FROM "table1_29063233_1" WHERE "uk_viewers_million"='6.09';