CREATE TABLE table_25127 ("Series #" FLOAT, "Season #" FLOAT, "Episode title" TEXT, "Written by" TEXT, "Directed by" TEXT, "U.S. viewers  ( millions ) " TEXT, "Original air date" TEXT)

Who is the written by when mark worthington is the director?
SELECT "Written by" FROM table_25127 WHERE "Directed by" = 'Mark Worthington'
SELECT "Written by" FROM "table_25127" WHERE "Directed by" = 'Mark Worthington'