My physics masters couldn't possibly be grand mages.

Einstein's consciousness wavered for a moment.

They came to a long corridor, with a deep red carpet stretching out beneath their feet. Wall lamps were placed every few meters. The air was filled with the smell of stale tobacco.

"This is the New Yorker Hotel, the thirty-third floor," Xia said. "Tesla stayed in room 3327 on this floor."

33 and 27 are both divisible by 3. But this is no coincidence. Tesla had a morbid obsession with the number "3".

Char and Einstein quickly found Tesla's room and knocked on the door.

There was no response. He knocked again.

This time, slow footsteps came from inside the door, and then the door opened a crack—the chain was still hanging.

An eye peeked through the crack in the door. It was greyish-blue, with a deep-set eye socket and a ring of deep wrinkles around it. The face looked much older and more haggard than Einstein's. The hair was completely white and disheveled.

"Who are you?" The voice was hoarse, filled with wariness and impatience.

Then, he saw Einstein standing next to Char.

He wasn't very familiar with Einstein and hadn't met him many times, but Einstein's appearance was so distinctive that he recognized him almost immediately.

"...Einstein?"

There was a hint of disbelief in his voice.

Einstein tilted his head slightly and twitched his lips as a greeting.

"You..." Tesla's voice trailed off. His gaze lingered on Einstein for a long time, then shifted away, glanced at both sides of the corridor, and returned.

How did you find this place?

"Someone is leading the way," Einstein said, tilting his head slightly in Char's direction.

Tesla's gaze returned to Char Aznable, then back to Einstein's face.

"What are you doing here?"

"I've come to see you," Einstein said. "There's something I'd like to ask for your help with."

Silence fell through the crack in the door.

Those grey-blue eyes stared at Einstein, as if judging whether his statement was true or false.

At that time, Einstein had already achieved great success and was revered at the Institute for Advanced Study in Princeton.

In 1937, Tesla was 82 years old, living in a small room at the New Yorker Hotel, surviving on meager royalties and occasional donations, feeding pigeons every day, and almost forgotten by the world.

It's obvious that the latter needs the former's help.

Tesla slowly closed the door. The chain clicked. The door opened again.

This time it's all open.

He stood in the doorway, wearing a wrinkled dark suit, collar open, without a tie. He was taller than Einstein, but as thin as a shadow.

"Come in," he said, his voice regaining its hoarseness.

The room was almost spotless, with three plates, three forks, and three napkins on the table—he had just eaten dinner, and everything was served in triplicate.

The pigeon stood on the windowsill, tilting its head to look at Xia, and cooed.

Tesla closed the door, walked to his desk, picked up a piece of bread, broke it into pieces, and placed them on the windowsill. Pigeons hopped down and began pecking at the bread.

He stood by the window, his back to Xia, and remained silent for a few seconds.

"So... what brings the renowned Einstein to me, an old man forgotten by the world?"

"The things you have done for humanity will not be forgotten," Einstein said sincerely.

Tesla holds the most patents for alternating current (AC), so theoretically everyone who uses AC would have to pay him a large patent fee.

But in order to make cheap electricity available to everyone, he tore up the patent documents that would have made him the world's richest man.

He was a true idealist and selfless contributor, and that alone is enough to earn him respect.

"Have you ever heard of...magic?" Einstein asked.

"Magic," Tesla repeated the word, then shook his head. "At least you used to wrap those absurd things in mathematics. Now you've even skipped that?"

Einstein wasn't angry; he simply shrugged and said, "My theory has been proven."

"Who confirmed this?"

"future."

Tesla's eyelids twitched. He turned to look at Xia Ya. He had actually noticed from the beginning that this young man had a unique temperament.

That kind of aura is hard to describe in a single sentence; it's somewhat like a... peculiar sense of alienation.

It's as if he's just a passerby in this world.

Or rather, it's rare to see such a confident and upright Asian person in the United States.

Einstein stopped playing coy and began to recount their experiences and their purpose.

The room was quiet for a while. Tesla remained silent, seemingly processing the information conveyed in those words.

Einstein earnestly said to Tesla, "Sir, the world, or rather, human civilization, still needs your continued contribution. I think you would not refuse this request if I were to relinquish my patent on alternating current for the sake of humanity."

After a brief silence, Tesla said, "Your theory is wrong."

Einstein was taken aback.

"Your theory says going back in time is impossible." Tesla glanced at Char. "He's standing right here. So you're wrong."

Einstein paused for a moment, then gave a slight, wry smile: "Perhaps."

Tesla continued, "According to the logic of time travel, when we come back next time, only a moment will have passed here, right?"

"Yes!" Char said.

Tesla nodded, as if confirming something insignificant.

He placed the last piece of bread on the windowsill and clapped his hands. Then he turned around and began to pack his things.

He first stacked the manuscripts on the table, aligning them page by page according to page number, and then tied them tightly with rubber bands. The edges of the manuscripts were curled, and some of the writing was blurred by water stains, but each page was filled with dense formulas and coil sketches.

He put them into a brown leather suitcase.

Then he went to the wardrobe and took out a few changes of clothes. Not many, three sets. They were folded neatly, the edges aligned as if measured with a ruler.

The pigeon cooed once inside the cage.

The Tesla paused for a moment and glanced at the windowsill.

"They go too," he said, not as a question.

Char nodded.

Tesla picked up the pigeon coop and placed it next to the suitcase. Then he took a pocket watch from the drawer, checked the time, and put it in his vest pocket.

"alright."

Char glanced at Einstein. Einstein nodded slightly.

Char raised his hand—

"Clatter".

A soft snap of fingers echoed in the empty room...

Tesla was momentarily stunned.

"Crackling and popping."

The crackling sound of the firewood brought Tesla back to his senses.

He looked at the roaring fire in the fireplace and felt the valley breeze blowing in through the window—he knew clearly that he was no longer in that hotel.