CREATE TABLE table_30383 ("\\u2116" FLOAT, "#" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" TEXT, "U.S. viewers  ( millions ) " TEXT)

Who wrote episode number 18?
SELECT "Written by" FROM table_30383 WHERE "#" = '18'
SELECT "Written by" FROM "table_30383" WHERE "#" = '18'