The Dementors no longer guard Azkaban, but they did for the entire thirteen years Sirius was imprisoned there.
Inside the house, Harry approaches Sirius. Sirius is lying in a bed, staring into space.
Harry walks up next to Sirius and looks at zem. Ze doesn't look back. Harry squints at Sirius, then waves zir hand in front of Sirius's face. Sirius just keeps staring.
PAST HARRY: Sirius Black!
Sirius looks up, surprised.
SIRIUS: L-Lily...?(hide transcript)