CREATE TABLE table_22363 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "U.S. viewers  ( in millions ) " TEXT)

What is the title when u.s. viewers (millions) is 3.97?
SELECT "Title" FROM table_22363 WHERE "U.S. viewers (in millions)" = '3.97'
SELECT "Title" FROM "table_22363" WHERE "U.S. viewers (in millions)" = '3.97'