"If you master the ability to change to an animal form, you will be able to master your Patronuses. A Patronus Charm is a shield, created by a powerful and positive memory. I must warn you, hard times are coming and that can make it difficult to conjure it. The memory you choose must be strong. Not a lot of Death Eaters can conjure one, the Dark Mark is dark magic and constantly feeding on the body and a person's magic, but difficult doesn’t mean impossible." He waves his wand and a bright bluish white doe hops through the room. It is beautiful.