Lin Ze squatted next to the piece of copper and slowly wiped it in a circle with his palm against the stone countertop.
The stone platform itself is very ordinary. It is just a flat surface carved out of the reef. It is rough, damp, and surrounded by many remains of marine life left here after low tide.
A corner of the stone platform was washed round and shiny by the sea water.
But the position where the copper piece was located happened to be embedded in a slightly concave stone groove, as if someone had deliberately stuck it there.
"How long has this been here?" Sirius came over and took a look.
"The rust color can be said to be hundreds of years at least." Lin Ze scratched the edge of the copper piece with his fingertips. Due to the frequent rise and fall of the tide, the copper piece was covered with oxidized green rust.
Mia carefully took out the copper piece from the stone trough and turned it over.
There is no writing on the back, only a shallow scratch, whether intentional or unintentional.
"What is this?" Lin Ze asked.
Mia stared at the symbol for a long time, frowning.
"I seem to have seen it somewhere..."
"But I can't remember..."
She put the copper piece into the side pocket of her backpack, "Let's take it home first."
Lin Ze nodded, stood up and looked around.
The arch was just a few steps ahead, and the water was just up to my ankles, and it was bitingly cold.
He took two steps towards the arch, and the stone slab under his feet suddenly shook slightly.
It was very light, like something heavy falling from a high place in the distance, and the shock was felt here.
"Do you feel it?"
Sirius pressed his hand on the stone wall and waited for a few seconds.
"It seems like the machine has moved again."
Lin Ze looked back at the stone steps behind him.
The stone steps have not changed, and the sea water has not continued to recede.
But on the originally plain stone slab in the arch, a vertical pattern appeared.
The vertical lines extend from top to bottom, about a foot long, and a piece of paper can probably be stuffed into the gap.
"When you came here last time, was there this arch here?" he asked Sirius.
"Last time?" Sirius was stunned for a moment, "Last time I didn't get here at all. The steps stopped there and I didn't go down any further."
Lin Ze took another half step forward, and the vertical lines suddenly lit up. A very faint silvery-white light came out from the gap, lasted for about two seconds, and then dimmed again.
"Back up." Mia's voice came from behind, with a urgency she rarely heard from.
Lin Ze did not hesitate and took three big steps back.
The silver-white light in the arch came and went quickly, as if someone flashed a flashlight in this direction.
"What did you see?" Sirius's hand was already on the wand, and his knuckles were white.
"Just a ray of light, coming out of that crack." Lin Ze poked his neck towards the arch again.
The vertical lines are still there, but they no longer shine, and the cracks are still so narrow. It looks like the stone slab has been pushed from the inside by some force, opening a hole.
Mia took half a step forward, raised the wand to his chest, and drew a small circle with the tip of the wand facing the arch.
A circle of light cyan light spread out from the tip of her staff and floated against the water towards the arch.
The halo stopped when it hit the frame of the arch, trembled slightly, and then dispersed into a mist.
"What a strange feeling..." Mia said softly.
"It's like... self-awareness..." Lin Ze looked at the arch with solemn eyes.
Lin Ze thought of the Veil in Ministry of Magic, the Veil that is always fluttering. Maybe he also has such self-awareness?
Mia tapped it lightly with the wand, and the arch once again lit up with silvery white light.
This time the light lasted for about five seconds and then dimmed.
Immediately afterwards, a small piece of stone peeled off from the stone wall next to the arch and fell into the water, making a "plop" sound.
Where the stone piece fell and was exposed, another piece of copper was exposed.
Lin Ze reached out and pulled the copper piece off the stone wall.
This piece of copper has more inscriptions than the previous one, but it is more severely corroded, and only a few characters can be barely legible.
"Look." He handed the copper piece to Mia.
Mia took it and looked through it twice, gently tracing the vague marks with his fingers.
"It seems different from the first piece, and there is a symbol engraved on the back."
There is a circle engraved on the back of the copper sheet, a dot drawn in the circle, and a horizontal line below the dot.
Sirius came over to take a look and suddenly said, "I have seen this symbol before."
"Where?"
"In the library of Black's old house, I used to play hide and seek with Regulus when I was a child. At that time, I thought the symbol was very beautiful and I even traced it with a pencil." Sirius's expression was very serious.
"I always thought it was something randomly carved by some old immortal like me, Black family."
"..."
Well, I have to say that these old brand Pure-blood families are still mysterious enough.
"Perhaps this arch is made of these copper sheets?" Lin Ze suddenly said.
Because the copper sheet shines with a light yellow luster after being peeled off.
The layer of light yellow luster sticks to the stone wall, with a regular shape, like the exposed corners of a small piece of copper foil embedded under the stone surface.
He picked the edge of the copper foil with his fingertips and pulled it out. The entire copper piece popped out with a "pop". It was about the size of a palm and much thinner than the previous two pieces. The surface was densely engraved with words, arranged in a ring.
Lin Ze turned it over and over twice, but could not recognize a single word.
What is engraved on the back is a tree, with the roots extending downward and the crown spreading upward. A horizontal line is drawn in the middle of the trunk, with a small dot above and below the horizontal line.
"World Tree." Mia suddenly spoke.
"Northern Europe The one in the myth?"
"Yes, Yggdrasil. Northern Europe In mythology, World Tree connects the nine kingdoms. The crown of the tree is the kingdom of God, and the roots of the tree are the underworld."
"So this tree means..." Sirius walked over and took a look.
"Some kind of connection between life and death?"
The vertical lines in the arch no longer glow, but they don't close anymore. There is just a gap open, like a half-closed eye.
"The crown of the tree is the kingdom of God, and the roots of the tree are the underworld..." He repeated Mia's words, rubbing his fingers back and forth on the horizontal line, "Then what is this line?"
"Midgard." Mia said, "In the Northern Europe myth, the middle layer of World Tree is the human world, which is where we live."
Sirius squatted by the water and used his wand to stir the water, causing a circle of ripples.
"The human world separates the world and separates the world of gods from the underworld..."
"A circle is a closed loop, the point is the starting point, and the horizontal line is the boundary. Anyone who crosses this line must become this line..." Lin Ze muttered.
Sirius raised his head. "What are you talking about?"
"Nothing." Lin Ze shook his head.
Lin Ze's eyes fell on the arch again.
The stone slabs inside the arch are darker in color and finer in texture than the stone walls outside. They feel unusually cold to the touch. The coldness penetrates through the fingertips and penetrates into the bones, like touching ice cubes. However, the temperature here is far from that low.