My physics masters couldn't possibly be grand mages.

"Phew—I'm dead."

Back at the villa, Xia collapsed onto the sofa, utterly exhausted, feeling as if his bones had been disassembled and reassembled.

Although I only stayed in the cave for a few hours, fighting in that kind of place with my nerves on edge was no different from doing strenuous exercise all day.

Einstein didn't say anything, but quietly sat down on the single sofa, took the pipe out of his mouth, and placed it on the armrest.

Tesla went straight to the kitchen, took three cups from the cupboard, and poured water from the kettle. His movements were unhurried and deliberate.

"You did a good job today," Einstein said. "You understood what I meant right away."

"If you don't understand, you'll die." Xia Ya tried to sit up straight and rubbed his sore shoulders. "In that situation, if your brain doesn't work quickly, you're doomed."

Tesla came out carrying a tray, placed the water cups in front of Einstein and Char respectively, picked up the last cup for himself, leaned against the edge of the desk, and did not sit down.

Xia took a sip of water, paused, and spoke with some concern.

"But wouldn't we be saying we've blocked our own escape route?"

In the past, a major reason they chose to enter the Tower of Truth this way was so they could escape back to 2072 at any time. But now, 2072 has a witch who can kill them at any moment.

"Yes," Tesla replied calmly. "But back then, you had to choose between betting on this world or betting on 2072. Didn't you?"

Xia didn't speak, but simply held the water glass in his hand and slowly twirled it. He knew Tesla was right, and that was why he cooperated with Einstein.

At the time, that might have been the only optimal solution.

Einstein didn't speak, but simply picked up his pipe, took a puff, and slowly exhaled. The smoke dissipated in the air, blurring half of his face.

He leaned back in his chair, seemingly waiting for the lingering scent of the cigarette to dissipate, before speaking: "It's not necessarily blocked."

Char raised an eyebrow. Tesla also turned his gaze from the window to him.

"What am I in Cindy's eyes?" Einstein asked.

"A super archmage capable of exiling her to another world." Tesla seemed to understand Einstein's meaning, a slight smile playing on his lips. "Interesting."

Char looked at this, then at that, and sighed helplessly.

"Can you guys stop playing games?"

Einstein tilted his pipe, tapped the edge of the bowl lightly with his fingertip, and the grayish-white ash fell precisely into the ashtray on the coffee table.

"Do you think she wants to come back?" he asked.

Xia thought for a moment and nodded. "No normal person would want to live in a foreign land, let alone a post-apocalyptic world."

"But if she wants to come back, she can only rely on you." Einstein looked at him, his grey-blue eyes holding a slow, unwavering certainty. "My only disciple, the 'Grand Magister'."

Xia was taken aback, his pupils suddenly contracting.

Tesla gently swirled the water in his glass. "You need to make her understand that you are the only 'key' she can use to leave that world. It's dangerous, but the rewards are immense. In order to come back, she will protect you and keep you alive."

"But what if she uses some kind of magic to control me?" Xia frowned.

Einstein smiled. "That depends on your wisdom. You can make her feel that I, the 'Grand Magister,' am constantly watching her every move. She'll be wary of me and will hesitate to attack you."

"She's very cautious," Tesla commented, his gaze falling on Char. "Otherwise, she wouldn't have been fooled by Einstein just now. If she were a reckless madwoman, none of us would have made it back alive."

Char remained silent for a moment, his fingers unconsciously tapping the sofa armrest. The only sound in the living room was the occasional crackling of the firewood in the fireplace.

He finally took a deep breath and looked up: "This risk... is worth taking."

"No rush." ​​Einstein picked up his pipe again, but didn't light it, just held it in his hand. "We're in a good position now, so we don't need to worry about any further probing. Let's figure out exactly what this 'witch' is all about."

"You should be able to find it in the library," Xia said. "Besides, I don't have to pay to enter the library now."

Tesla placed his water glass on the table and straightened up: "If possible, it's best to be prepared before you go."

"That woman is probably at least level six," Xia Ya said with a helpless smile. "What's the point of making any preparations?"

Tesla didn't reply, but simply took his water glass and walked to the window, his gaze falling on the valley outside, which was gradually darkening.

"More than this..." he suddenly spoke, his voice low, yet it made both Xia and Einstein look at him simultaneously, "Have you ever considered who planned all of this today?"

While on the road, Char actually compared some of the information they had gained with the two of them, and they both agreed with Char's deduction.

"Whoever it is," Einstein said, taking a sip of his water, "will come looking for us soon."

Xia was taken aback, before he could ask why.

"Knock knock".

There was a knock on the door.

Char glanced at Einstein and Tesla, then got up, walked to the door, and opened it.

Char subconsciously looked up.

Monra stood outside the threshold, his two-meter-tall frame completely filling the doorway. He wore a coarse linen off-white robe and walked barefoot on the stone steps, the twilight spreading out in a gray-blue hue behind him.

Char instinctively took a half step back.

Monra lowered his head slightly. His dark-skinned face was expressionless, with deep wrinkles running from his nose to the corners of his mouth, as if etched by a knife.

He didn't speak. He didn't move.

Just standing there.

The air seemed to grow heavier.

Two seconds, or maybe longer, passed before Monra turned slightly to the side, his gaze passing over Xia's shoulder and landing on the two elderly people in the living room.

"Aren't you going to invite me in?" His voice was low.

"Oh, please come in." Xia Ya quickly took a step back, while Meng La took a few steps forward.

Char felt as if the ground was trembling slightly when he walked.

"Monra," Monra said, looking at Einstein.

"Albert Einstein." Einstein nodded, sat up straight, and said, "Please sit down."

Monra did not sit down. Beneath his white eyebrows, a pair of unfathomable black eyes watched him silently, as if trying to see through the emotions hidden beneath his calm exterior.

But... nothing was gained.

"I appointed you to be the chief proctor for this exam."

Einstein raised his eyebrows and then slowly nodded.

"So it was you."

His tone held neither surprise nor displeasure; he simply said, "Should I then say...it's an honor?"

Although he was calm, Monla could detect a hint of dissatisfaction in his words.

He could understand; after all, no one likes to be manipulated. He had been mentally prepared from the moment he devised the entire plan.

"In the forbidden book section of the Tower of Truth, on the third floor, there is a library that is not open to any professors. From today onwards, you and your students may enter and exit at any time."

Einstein offered no comment, but simply pointed to Tesla and asked, "And him?"

Monra glanced at Tesla. "As long as you can take responsibility for their safety."

"And..." Einstein raised his eyes, his grey-blue gaze landing on Monra's face, "Next time you want to have these 'novel experiences,' should you give me a heads-up beforehand?"

His tone wasn't harsh, but he wasn't really asking for opinions either.

Monla was silent for a moment.

"it is good."

He turned around, stepped barefoot onto the wooden floor, and walked towards the door.

However, just as he was about to reach the door, Monla paused for a moment and turned to look at Einstein.

"Didn't you tell Meredith before that light is both a wave and a particle?"

Einstein nodded. "That's right."

"Isn't that contradictory?"

"It's a contradiction," Einstein said, "but it's also true at the same time. We just need to look at it from a different perspective."

Monla frowned slightly, but Einstein continued speaking.

"You can imagine a cylinder that looks like a rectangle from the front and a circle from the side. Are a rectangle and a circle contradictory on a single sheet of paper?"

Monla thought for a moment and said, "It's a contradiction. We can't draw a shape that is both a rectangle and a circle."

"But the cylinder itself is not contradictory," Einstein said calmly, as if stating some common sense. "It simply presents different shapes from different perspectives."

"The wave-particle relationship of light is similar; based on macroscopic experience, the intuitive concepts of 'wave' and 'particle' are contradictory. But in the microscopic world, 'wave' and 'particle' are simply different 'shapes' projected onto our experimental apparatus."

The living room was quiet for a while. A thoughtful expression appeared on Monla's face. Many doubts and questions gradually began to form in his mind.

His brow relaxed as he spoke to Einstein.

I owe you a favor.

After saying that, he turned and left, disappearing into the night...