Dumbledore fell silent.
This silence lasted until they reached the center of the field.
At this moment, Sean would know that in the face of love, saints and mortals are no different, and the greatest wizard in the magical world is no different from a Muggle.
"Let's do it right here. Our first Defense Against the Dark Arts lesson.
"It's hard to imagine I still have students to teach. What a responsibility to look forward to..."
Dumbledore said, seeming to revert to the kindly figure in Sean's memory.
He waved his wand and conjured an old wardrobe.
Dumbledore walked over and stood beside the wardrobe, which suddenly began to shake, banging against the wall.
"Do you know what's inside?"
Dumbledore asked calmly.
"I believe there's a Boggart inside."
Sean replied.
"Ah, yes. Boggarts like dark, enclosed spaces,"
Dumbledore spoke as if lecturing students,
"Wardrobes, the gap beneath a bed, the cupboard under the sink... Now, my first question for you is: What is a Boggart?"
"It is a shape-shifting creature that will turn into whatever it thinks will frighten us most."
Sean's voice grew lower and lower, feeling increasingly that this was too cruel.
"Yes, I suppose I couldn't have put it more clearly myself."
Dumbledore said,
"So, the Boggart sitting in the darkness within has not yet assumed a form. It does not yet know what will frighten the person on the other side of the door. Nobody knows what a Boggart looks like when it is alone, but when I let it out, it will immediately become whatever each of us fears the most. This means,"
Dumbledore continued,
"We have a huge advantage over the Boggart. Sean, have you spotted it?"
"Yes, Professor—because there are two of us, it won't know what form to take."
"Precisely."
Dumbledore nodded,
"It's always best to have company when you're dealing with a Boggart.
"It becomes confused. Should it become a headless corpse or a flesh-eating slug?
"I once saw a Boggart make that very mistake—it tried to frighten two people at once and turned itself into half a slug. Not remotely scary.
"The charm that repels a Boggart is simple, yet it requires force of mind.
"You see, the thing that really finishes a Boggart is laughter. What you need to do is force it to assume a shape that you find amusing.
"Now, I will teach you the incantation. Repeat after me... Riddikulus!"
Dumbledore missed this feeling. Long ago, his students were Newt and Leta;
Not so long ago, his students were James, Lily, and Severus;
Now, his student was Sean Green... He liked this student very much. Sometimes he saw the things he loved most in his student.
"Riddikulus!"
Sean seemed quite adaptable to Headmaster Dumbledore's sudden instruction.
"Very good. Now, let's try it. Step back a bit, Sean."
Sean retreated to the side of the cabinet, leaving only Dumbledore standing before the wardrobe.
A string of sparks shot from the tip of Dumbledore's wand and hit the spherical doorknob.
The wardrobe door burst open, but no monster sprang out. Instead, there was only a bewildered and gentle witch, looking timid and lovely.
But the moment Dumbledore saw her, he turned his head away. Sean quickly drew his wand, and the cabinet door slammed shut in the blink of an eye.
"You didn't need to do that."
Sean frowned.
He had guessed early on how the old wizard intended for him to see Ariana.
It was by letting him see the old wizard's greatest fear—his Boggart, his sister, the dead Ariana.
"Oh, it doesn't matter..."
Dumbledore sat on the grass, his beard still trembling slightly,
"Sit here. Come, child. Let me tell you a story."
The wind blew gently, and clouds rolled and unrolled over the fields.
"There was once a wizard, a wizard whom we should all despise.
"His sister was attacked by Muggles because she accidentally revealed her magic.
"This attack left her mentally unstable, unable to control her own magic.
"His father was furious. seeking revenge, he cursed those Muggle boys and was arrested for it.
"He died a miserable death in Azkaban.
"But what about him? He was talented. One had to admit he was brilliant. So he wanted to escape. He wanted to excel. He wanted to shine.
"Look at what he did. He was soon in frequent correspondence with the most famous magical masters of the day, including the celebrated alchemist Nicolas Flamel, the renowned historian Bathilda Bagshot, and the magical theoretician Adalbert Waffling.
"Several of his papers found their way into scholarly publications like Transfiguration Today, Challenges in Charming, and The Practical Potioneer.
"Before graduation, he and another equally brilliant wizard, Elphias Doge, planned to travel the world right after school.
"They were already in Diagon Alley preparing to depart for Greece when news came of his mother Kendra's death—his mother died caring for her sister.
"So, he could only abandon his plans to travel the world and return home to care for his sister."
Dumbledore's narration was frank and detached. At this moment, his gaze swept over Sean's head, looking towards the distant valley.
"So he resented it all.
"After his mother died, he was left responsible for a damaged sister and a wayward brother. He returned to the village full of resentment and bitterness.
"He thought he was trapped and wasting his life!
"But he forgot that his brother had always shouldered his responsibilities. Only his brother could calm his sister when she lost control of her emotions, yet he simply forgot...
"His brother was furious at his selfishness—
"Think about it. He actually wanted to leave here with another person, to escape this place, to escape the place that trapped him.
"He was too selfish, Sean, more selfish than a very selfless person like you could ever imagine.
"Then... reality appeared in the form of his rough, uneducated, yet far more infinite brother.
"He didn't want to hear the truths his brother shouted at him. He didn't want to hear that he couldn't go and complete his plans because he was dragging along a frail and unstable sister—plans to make Muggles submit, to make wizards great!
"The argument between him, his companion, and his brother escalated into a duel. His sister... after all the care and attention his mother and brother had given her... fell to the ground, dead."
"His companion fled, leaving only him to bury his sister and learn to while away his days in guilt and extreme sorrow. That was the price of his shame."
Dumbledore smiled. That smile was as bitter as straw in a wheat field, hanging with a fragile strength.
This was his entire life: constantly saying goodbye, running away, trying to forget yet never wanting to forget. In the end, his hands were empty, and his heart was scarred.