Each year on February 14, millions of people celebrate the world's largest festival of love with boxes of chocolates, candlelit meals, and notes of affection. But behind the rosy facade of Valentine's Day is a mysterious -- and grisly -- tale of a beheading and body parts scattered across Europe. The Catholic martyr St. Valentine was beheaded on that date in the third century, supposedly for breaking a Roman ban on performing marriages. Now in Dublin a church claims to exhibit St. Valentine's heart; in a Rome basilica his supposed skull is displayed; in a Glasgow friary his skeleton sits in a golden box; in a Prague basilica his shoulder bone is an attraction; and in a Madrid church his remains are encased in glass.