CREATE TABLE table_9773 ("Episode #" TEXT, "Original airdate  ( UK ) " TEXT, "Episode title" TEXT, "Doctor Who episode" TEXT, "Webcast link" TEXT)

Which Episode title has a Episode # of s2?
SELECT "Episode title" FROM table_9773 WHERE "Episode #" = 's2'
SELECT "Episode title" FROM "table_9773" WHERE "Episode #" = 's2'