Narnia is a magical world that Lucy Pevensie discovered by chance while playing a game of hide and seek. It is led by a mysterious Emperor, who operates through Aslan, an extremely benevolent lion. There seem to be many portals into Narnia, including Professor Diggory's wardrobe and the London Underground. In the third film, The Voyage of the Dawn Treader, a painting is another portal into the Narnian world.