Dumbledore immediately turned around, and the two returned to the Headmaster's Office.
The portraits, who had been about to greet them, murmured in confusion at the looks on their faces, then gradually fell silent.
Every gaze remained fixed firmly on the two of them.
Zhang Xiao casually conjured a stand, mounted the Far-Seeing Mirror on it, then flicked a finger, projecting its image into the air.
His puzzled father appeared, along with his mother and grandfather, who had just arrived.
Dumbledore and the Old Celestial Master exchanged slight nods of greeting. Then Dumbledore interlaced his fingers on the desk and quietly waited for Zhang Xiao to speak.
Zhang Xiao took two deep breaths and slowly calmed down.
The shock and despair of suddenly hearing about the apocalypse gradually subsided, and his thoughts immediately turned to whether there was any way to avert it.
"Professor, do you remember this letter?"
Zhang Xiao took out the letter from Slytherin that he had received in his first year and spread it on the desk.
Dumbledore nodded.
"The apocalypse mentioned in the letter is real. I found Slytherin. The only reason it hasn't happened yet is that Slytherin has been blocking its source.
"But now he can't hold it back anymore!"
Dumbledore's white eyebrows twitched, and he asked solemnly:
"Have you confirmed this?"
"He's already become a mass of rotting flesh and can't communicate. I also met his wife, Oselia Slytherin.
"She was also the source of the Dementors..."
Zhang Xiao paused, then began recounting everything in Chinese, since Dumbledore could understand it too.
He began with the journal found in Tom's castle, explaining how his interest in the ancient gods had led him to the Pyramid in search of clues, where he had discovered an enormous underground space.
There, he had also found