CREATE TABLE table_661 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "Original air date" CLOB, "U.S. viewers  ( million ) " CLOB)

What's the season number of the episode watched by 0.57 million US viewers?
SELECT MAX("No. in season") FROM table_661 WHERE "U.S. viewers (million)" = '0.57'
SELECT MAX("No. in season") FROM "table_661" WHERE "U.S. viewers (million)" = '0.57'