CREATE TABLE table_2578 ("No. in series" CLOB, "No. in season" CLOB, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "Production code" CLOB, "U.S. viewers  ( millions ) " CLOB)

How many million U.s. Viewers watched episode 12 in the season?
SELECT "U.S. viewers (millions)" FROM table_2578 WHERE "No. in season" = '12'
SELECT "U.S. viewers (millions)" FROM "table_2578" WHERE "No. in season" = '12'