CREATE TABLE table_21824 ("No. in series" FLOAT, "No. in season" FLOAT, "Title" TEXT, "Directed by" TEXT, "Written by" TEXT, "Original air date" TEXT, "Production code" FLOAT)

When did 'secrets' air?
SELECT "Original air date" FROM table_21824 WHERE "Title" = 'Secrets'
SELECT "Original air date" FROM "table_21824" WHERE "Title" = 'Secrets'