CREATE TABLE table_26764 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "U.S. viewers  ( million ) " TEXT, "Original air date" TEXT, "Production code" TEXT)

What episode number in the series had 2.77 million U.S. viewers?
SELECT MAX("No. in series") FROM table_26764 WHERE "U.S. viewers (million)" = '2.77'
SELECT MAX("No. in series") FROM "table_26764" WHERE "U.S. viewers (million)" = '2.77'