Suddenly from around the auditorium, the feel of a breath of the wind. Some black robes arise around people. Black robes that become black shapes. That become Dementors.
Flying Dementors through the auditorium. These black deadly shapes, these black deadly forces. They are everything to be feared. And they suck the spirit from the room.
The wind continues. This is Hell. And then right from the back of the room and whispering around everyone. Words said with an unmistakeable voice.


The voice of VOLDEMORT...
Haaarry Pottttter...

Harry’s dream has come to life.

Harry Potter and the Cursed Child - Chapter 2 :
See this quote in the Pensive -