CREATE TABLE table_27811555_1 (directed_by VARCHAR2, us_viewers__millions_ VARCHAR2)

who directed the episode that 6.3 million u.s. viewers saw?
SELECT directed_by FROM table_27811555_1 WHERE us_viewers__millions_ = "6.3"
SELECT "directed_by" FROM "table_27811555_1" WHERE "6.3" = "us_viewers__millions_"