CREATE TABLE table_30920 ("No. overall" FLOAT, "No. for series" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "UK viewers  ( million ) " TEXT)

Who directed the episode with UK viewership of 6.09 million?
SELECT "Directed by" FROM table_30920 WHERE "UK viewers (million)" = '6.09'
SELECT "Directed by" FROM "table_30920" WHERE "UK viewers (million)" = '6.09'