CREATE TABLE table_23825 ("Series #" FLOAT, "Season #" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( in millions ) " TEXT)

What series was directed by Mark Roskin?
SELECT MIN("Series #") FROM table_23825 WHERE "Directed by" = 'Mark Roskin'
SELECT MIN("Series #") FROM "table_23825" WHERE "Directed by" = 'Mark Roskin'