In an unknown col, there is a three-story building built in the 60s of the last century, hidden in the dense mountain forest, and the yellowing creeper has almost completely covered the exterior wall of the Soviet-style building, and even the originally small windows are tightly covered by the leaves of this vegetation, making it difficult to observe the inside of the building from the outside.

There is a guardrail more than one person high on the periphery of the small building, and the iron guardrail has long been rusted in the wind and rain for more than half a century, and all kinds of nameless vines and plants are entwined on it, and even a few small flowers that are not red or white are sparsely bloomed.

The fenced yard is covered with withered yellow weeds, an ancient Beetle car parked in the yard, although the car shape is the appearance of the fifties and sixties of the last century, the paint and plating parts of the body are very well maintained, the whole car looks at least seventy percent new, the front window glass and chrome bumper are even more polished, which shows that the owner of this car cherishes her car.

The wooden door to the interior of the building was tightly closed, and a large rusted lock hung from the door, apparently, this door

It hadn't been opened for years since it was last closed, and through the dusty and stained glass embedded in the door, a dark cobweb-covered corridor could be seen.

On the wall of the sunny side of the building, there is a spiral lifeladder full of green vines, two black garbage bags are thrown at the staircase on the first floor, and the fallen leaves on the steps leading directly to the second and third floors are cleaned, which seems to indicate that the small building is still inhabited.

"Jingle Bell ――――――"

Suddenly from somewhere inside the building there was the sound of an old-fashioned telephone ringing, a metallic ringing sound from a room on the second floor—two rows of opposite bookshelves each occupying two walls of the room, and the shelves were filled with books, animal and plant specimens, human bones, and some strange ancient artifacts. These objects of unknown origin and numerous books filled the shelves and continued to occupy the space on the floor, divided into three or four piles and piled up on the floor in an irregular manner, making the originally spacious room seem much narrower.

The two remaining walls in the room were also facing each other, with a desk stacked on top of each other by the doorway with five or six blade servers connected by a large mess of cobweb-like wires, a small cathode ray tube display showing an application window, and the LED lights of the modem and router hanging on the wall flashing constantly, and I didn't know what the blade servers were doing.

Next to the cathode ray tube display was the old dial telephone landline that was ringing loud, and it was still screaming wildly, apparently patient.

At the base of the wall facing the door was a large table, on which almost all the objects next to each other were unrelated, stacked almost half a meter high in each other, almost completely submerging the woman who was sitting at the table and examining an ancient book with a magnifying glass.

The woman was wearing a slightly old but still neat white coat, her hair was coiled up and tied into a bun at the back of her head, pinned with a red agate hairpin, but a strand of hair was deliberately left hanging down in front of her forehead, a rather fair-skinned melon seed face, looking about twenty-five or sixteen years old, with a pencil behind the right ear, slender willow eyebrows slightly wrinkled, and a pair of red phoenix eyes obviously showing an impatient look.

"Damn...... It's just that calling at this time is really making a mess for the old lady......" The woman angrily dropped the ancient books and magnifying glass in her hand, kicked the foot of the wall with her feet under the table, and the seat with wheels slid backwards, she turned around, stretched out her legs and bounced out of the chair, and walked quickly to the position of the telephone.

Just a few steps, the woman didn't know what was tripped under her feet, although her skills were still agile and hurriedly stood firm on the table, but in the stumbling knocked down a pile of debris on the ground, and suddenly the pile of books nearly one person high collapsed, and a wooden box stacked on top of it fell to the ground and broke open the lid, and large and small beads and metal coins of unknown material rolled around inside......

Ignoring this, Dr. Shi stabilized his body and walked quickly to the old telephone, because the number of this phone was only known to a very small number of people, and these people were all extremely important to her.

Grabbing the telephone and putting the receiver to his ear, Dr. Shi asked, "Hey, who are you looking for?"

"Hello, is Dr. Shi there?" On the other side of the line came the voice of a very young girl, her voice was very special, slender, pure, slightly sweet, like the gently plucked strings in the quiet room, even as a woman, Dr. Shi felt very pleasant to hear.

Dr. Shi couldn't help but feel a little strange, judging purely from her voice, she never knew a girl with such a beautiful voice in her impression, this girl was definitely not one of the important contacts who knew her contact information, where did she get her phone number?

"Hello, I'm Dr. Shi. After a moment of hesitation, Dr. Shi confirmed his identity to the other party. "Who are you, what are you looking for me, and where did you get this phone number?"

"Uh...... Doctor Shi, don't you remember me? I'm Cheng Xiaonan!" After confirming Doctor Shi's identity, the girl's voice was a little excited: "I've been looking for you everywhere for so long, but I can't find you anywhere, this phone number is the ...... I got from your friend Mountain Soul"

"Oh...... Soul of the Mountain......" Hearing this unfamiliar screen name, Doctor Shi's heartbeat involuntarily accelerated. Since the return of the dragon's spine in the sea of clouds, the two of them have not been able to meet again since the disbandment of the treasure exploration team, occasionally talking on the phone, and always talking about some topics that don't matter, as if the adventure of two people living and dying together has long been drowned out by the comfortable days of the city, perhaps, he has forgotten what the two people once said at the moment of life and death......

Wait! Cheng Xiaonan! How does this name sound so familiar! Doctor Shi suddenly jumped out of his sweet and bitter thoughts. By the way, I remembered! Cheng Xiaonan, isn't that the boy who entrusted me to treat my paralyzed girlfriend!

Cheng Xiaonan, Dr. Shi remembered him, it was a tall and thin, white and clean little boy, the child had a delicate face, a pointed chin, a pair of eyes full of melancholy in the pupils, a messy hair looked a little unkempt but had a unique style, although the figure was slightly thin but the skeleton was very strong, standing there like a tall poplar......

Today, this Cheng Xiaonan is a girl's voice, is it the same name and surname?"Cheng Xiaonan? Which Cheng Xiaonan?" Dr. Shi had doubts about the girl's identity; "I do know a person named Cheng Xiaonan, but it was a boy, I don't remember knowing a girl named Cheng Xiaonan......"

"Uh...... Doctor Shi, actually...... Actually, I'm the man you said Cheng Xiaonan!" The girl's voice on the other side of the phone seemed a little anxious. "I have something very important to ask you ......"

Doctor Shi was stunned for a moment, and then laughed: "I said, you are clearly doubting my IQ! Obviously it is a girl's voice, how can you be a boy, no matter how stupid I am, I will never be unable to figure out how much difference there is between male and female voices, don't tell me that you are a man, but your voice sounds like a girl, even if you use voice changing software, it is impossible to have such a perfect girl's voice!"

On the other side of the phone line, the girl who called herself "Cheng Xiaonan" was silent, and she didn't speak for a long time, and Dr. Shi could only hear the sound of thin breathing coming from the earpiece. After a long time, the girl finally spoke again: "Doctor Shi, whether you believe it or not, I am indeed the Cheng Xiaonan who entrusted you in the first place, maybe my voice has become completely unfamiliar, and you may not even recognize me when we meet, but the fact that I am Cheng Xiaonan is absolutely true! Doctor Shi, do you remember that morning, you and I met in the park, and in the face of your repeated prompts, the decision I made? That decision that cannot be regretted?"

That morning? That ...... A decision that cannot be regretted? Oh yes, I remember......

Dr. Shi held the phone in her hand, and a past that was not too long ago appeared in her mind like a film movie.........