CREATE TABLE table_23860 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directedby" TEXT, "Writtenby" TEXT, "Originalairdate" TEXT, "Production code" TEXT, "U.S.viewers  ( million ) " TEXT)

what is the maximum number in the season wher the us viewers is 2.59?
SELECT MAX("No. in season") FROM table_23860 WHERE "U.S.viewers (million)" = '2.59'
SELECT MAX("No. in season") FROM "table_23860" WHERE "U.S.viewers (million)" = '2.59'