Here are the latest two sketches, a Dementor (a Guard of Azkaban wizarding prison) and Sirius Black (an escaped prisoner).
The Dementors are rather skeletal in appearance, wafting through the air in ragged cloaks. They will inhale your essence, taking all the joy and good memories you have, leaving you with only the feelings of sadness, misery, or despair of your life. Their arrival is announced by an icy frost that overlays anything with moisture, including one's breath. The atmosphere feels as if "all the joy had gone from the world" when they are near. As a punishment for his escape, the prisoner is sentenced to the "Dementor's Kiss" -- they'll suck out his soul!
A Dementor's face, as it attacks Harry, hundreds of feet in the air, causing him to fall.
Meanwhile, the escaped prisoner, Sirius Black, has been tracking his prey, at Hogwarts. Harry has been warned that Black wants revenge, and to kill him. He, Hermione, and Ron all end up trapped in a haunted shack, along with Ron's pet rat, Scabbers. Who is behind that door that has just closed? Emerging from the shadows ... looking ragged and weary, "reflecting the madness within" -- it's Sirius Black!
Will Sirius attack Harry? Will someone come to the rescue, and if so, who will be rescued?
(From Harry Potter and the Prisoner of Azkaban. Gary Oldman as Sirius Black.)