CREATE TABLE table_28424 ("No." FLOAT, "Title" CLOB, "Directed by" CLOB, "Written by" CLOB, "U.S. viewers  ( million ) " CLOB, "Rank  ( week ) " FLOAT, "Original air date" CLOB, "Production code" CLOB)

Who wrote the episode with 18.07 million viewers?
SELECT "Written by" FROM table_28424 WHERE "U.S. viewers (million)" = '18.07'
SELECT "Written by" FROM "table_28424" WHERE "U.S. viewers (million)" = '18.07'