The walls here are black, the floor tiles here are black, the ceiling here is black, and the twelve doors here are also black.

They are equidistant inlaid around the circular room and on the curved brick wall.

In fact, there are some metal lamp racks on the wall, with three candles on each shelf. But the original dark blue candle has been extinguished, making the room deep underground that has not been occupied by the fog as dark as the night in the fog... No, it may be darker than that, because everything here is black.

With a wave of her hand, Maka opened the fence door of the magic elevator that could not be opened automatically, and came in with a soft light in her other hand.

"In fact, I've always wanted to come here and walk through every room, because there are many magic mysteries that may not be useful, but most of them are very complex and interesting."

Maka led Sarah, who was closely behind him, and walked in, saying to herself:

"Look! Behind that door is the planet room, which should be built by some ancient wizards who liked to study astronomy with magic. Entering it is like entering the cosmic starry sky. But some planets are not stable because of magic for too long, such as Pluto, which often explodes..."

"I think the room next door can be called the 'brain Hall', which I guess should have something to do with your alchemists - there is a huge glass water tank with a brain activated by Alchemy. I guess that may be another way of pursuing 'eternal life' considered by ancient alchemists..."

"The next room..." Maka said, moving her arm to the left and pointing to the third door, "Oh, it's the time hall. I've been to it several times... I feel like I have a subtle fate."

He didn't seem to want to introduce Sarah to the situation in the time hall. He just passed by in one sentence. Soon his finger pointed to the fourth black door.

"Yes, it's this one. That's right." Marca nodded. "Professor Dumbledore said that there is a power 'more magical and terrible than death, wisdom and nature', and... It's also a very important power missing in your soul."

"Is that the 'love' you mentioned before?" Sarah said immediately.

"It's just what Professor Dumbledore calls it," Marca said. "In fact, I don't quite understand its essence... I just think it can be 'love', but it can also be 'sin'."

The voice dropped a little. When Sarah heard it, she couldn't help looking confused and thinking. Maka walked straight towards the door step by step.

"In the past, I wanted to pay attention to them, but it was not very convenient because it was the Ministry of magic; later, I didn't have that spare time... Even today, I can only take a look at this one first. The rest depends on whether I have that chance in the future."

Then he reached out and gently stroked the black door.

"By the way, it's locked... In Dumbledore's words, 'always locked'."

"No one opened it?"

Sarah finally stopped thinking, which seemed meaningless to her, and approached the door.

"To be exact, it's' no one can open '." Maka said. "Most of the buried buildings of the Ministry of Magic have been repaired and rebuilt, but the mysterious affairs department has always maintained the appearance of the wizard Council. For nothing else, it can't be changed only by modern wizard means, including the locked door."

While talking, his palm was still gently close to the door, carefully exploring the secret that the door could not be opened.

"Oh, suddenly, I think I should say sorry to you." Maka said casually, "I didn't just bring you here to replenish your soul. I also have my own purpose - you asked me why I didn't hide and concentrate on studying, didn't you? In fact, the power hidden behind this door may enable me to find out the true meaning of the soul rules first. While helping you, I'm also helping myself. That's what I said at that time "Mutual use."

At this point, he suddenly stared at the door in front of him, blinked, and then suddenly showed a smile.

"I see."

"Do you have a way to open the door?" Sarah asked immediately.

"No," Marca shook her head, "don't open the door - I seem to understand that this door may be just a 'symbol'. Just as the power here is just a 'symbol'."

As soon as he finished, he suddenly bent down slightly, gently took Sarah's wrist, and slowly put the latter's palm on the door.

"Put your hand on it, which should help you feel the 'power' of the head more easily - close your eyes, open your mind, don't resist, try to feel it."

After helping Sarah finish all this, Maka followed her and closed her eyes slightly. They touched the door and stood there quietly.

Time passed bit by bit. It was quiet and there was no sound around. It was as if the whole world was far away from them.

Unknowingly, Sarah only felt that her consciousness, which had been very clear since her birth, was slowly blurred here.

"What is this... Feeling?"

A moment later, Marca couldn't help but open her eyes a little and look at Sarah next to her. Then he couldn't help but secretly eyebrow.

"So fast?" he whispered, "well, although it's a 'defective product', it's a pure and incomparable soul created by the peak alchemy - the 'door lock' won't do much to her. By comparison, I'm more like a failed work."

Obviously, Maka has really understood the essence of the door and the "lock" on the door.

In fact, the so-called "door lock" comes from the "lock" in the heart of everyone standing in front of the door trying to enter. When you think it is locked, it is locked. The more defensive people are, the more difficult it is to enter the "door".

The pure and transparent soul like Sarah may not need the guidance of Maka just now. She can enter it by herself.

But for Maka, it's a little difficult.

"The idea is right. It's not wrong to bring her," he sighed as he looked at the closed door. "I just missed a little... My words may not open this door... Even if I understand its principle."

"Unless -"

Suddenly, he withdrew his hand, looked down at his palm and thought about it secretly.