CREATE TABLE table_16464 ("No. in season" FLOAT, "No. in series" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( million ) " TEXT)

Who wrote the episodes that were viewed by 2.12 million viewers?
SELECT "Written by" FROM table_16464 WHERE "U.S. viewers (million)" = '2.12'
SELECT "Written by" FROM "table_16464" WHERE "U.S. viewers (million)" = '2.12'