CREATE TABLE table_31407 ("No. for season" FLOAT, "No. for series" FLOAT, "Episode" TEXT, "Airdate" TEXT, "Viewers  ( in millions ) " TEXT)

Which episode is number 3 in the season?
SELECT "Episode" FROM table_31407 WHERE "No. for season" = '3'
SELECT "Episode" FROM "table_31407" WHERE "No. for season" = '3'