Kisses aren't normally associated with sucking the happiness from your soul, but in the world of wizards nothing is what it seems. In the Prisoner of Azkaban, Harry and Sirius Black find themselves by the Black Lake surrounded by Dementors, and are almost left for dead. However, Harry catches a glimpse of a familiar figure across the way who summons a Patronus in the shape of a stag, which finally drives those evil Dementors away.