The principle is actually very simple, using light reflection to survey footprints.

In the criminal investigation of later generations, it was possible to use the strong light of the footprints, but the Great Yan Dynasty did not, and Shi Yong could only use torches and mirrors to achieve the effect, so that the footprints on the tiles were presented (see digression for annotations).

Under the reflection of the torches and mirrors, the angle of light changed, and a few messy footprints on the tiles appeared in front of everyone. It's just that under the dripping rain, it's not clear.

"Paper!" Shi Yong shouted again.

This time, although she didn't know what she was going to do, Yang Fei was obedient and quickly went to the mayor's house to get a few blank pieces of paper.

Shi Yong covered the footprints with white paper, and the rain-soaked footprints quickly stretched onto the paper.

The texture of the sole is not clear, but the length of the shoe can be preliminarily judged.

"It's a man."

Yang Fei shouted for the first time.

Shi Yong ignored him and made several footprints on the roof for comparison.

"It's the same sole."

Zhu Jiu held the torch and was surprised to see her doing this, "Ah Shi is really capable, how can you understand this?" ”

Shi Yong glanced at Song Changgui, who was silent, "My father taught me." ”

Song Changgui's eyelids jumped, and he looked at her smiling eyes for a moment, without saying a word.

Zhu Jiu couldn't help but admire, "Song Cheng is really condescending." ”

"In this way, it is the same man's foot money. What about female ghosts? Yang Fei's doubts are often different from others, he touched his chin and asked, "Why are there no footprints of female ghosts on the roof?" The female ghost ......"

Is it a real ghost?

Shi Yong glanced at him and handed the rubbed white paper to Song Changgui, "Dad, what do you think?" ”

Song Changgui pondered for a moment: "In the thirteenth year of Yonglu, there was a case in Shuntian Mansion, which was committed with big feet and small shoes. This...... At first glance, they look like footprints of the same size, but they may not be the same person. It's just that this rain is not at the right time, and I can't see more specific. ”

This kind of thing, Shi Yong didn't want to be in the limelight, and put all the credit on Song Changgui.

"Dad has a point. The daughter was taught. ”

Zhu Jiu said with a smile: "Song Cheng has a good memory, do you remember the events of more than 20 years ago?" ”

Song Changgui was praised uncomfortably, and laughed suddenly, "That year, when the eldest princess got married, I just arrived at the Yamen on an errand, and I have a deep memory. ”

Several people discussed the case, and it was still unclear whether there were female ghosts or not. But Yu Chang will not run to Shuishui Alley to hang himself for no reason, and what important thing he said to his mother before leaving home is now a mystery.

"Did Yu Chang know any secrets, or remembered the murderer, so he was killed?"

Yang Fei likes to ask questions, but no one answers him.

Because of this problem, everyone knows it in their hearts.

Judging from the words he said when he went to the Wuqi Pavilion during the day, his death was related to the case of Zhang Zhu's quick destruction.

Darkness enveloped the house.

Several families in the neighborhood have moved away, and it is very lonely at the moment.

Shi Yong saw Zhao Yin standing at the corner of the eaves and watching the pond silently, so he slowly walked over and approached him, pretending to be close.

"The Metropolitan Governor won't doubt me anymore, will he?"

Unexpectedly, Zhao Jun took a step back expressionlessly and distanced himself from her.

"You want to hear the truth?"

Shi Yong snorted, "Yes." ”

"You're still suspicious."

“……”

Zhao Yin paused, looked at Shi Yong's aggrieved look, and changed the topic coldly: "Do you think of acupuncture?" ”

Shi Yong glanced at him lazily, "That's why I asked you why you came, and you said it was going to rain?" ”

Zhao Yin's eyes narrowed slightly, and he didn't deny it, "Otherwise?" ”

Shi Yong laughed, "I thought that the adults knew that it was about to rain and felt sorry for my body, so they specially brought an umbrella for me, but I didn't expect it to be so cold, just to take advantage of my ......"

Her tone was relaxed and teasing very naturally, as if she and Zhao Yin could have been so comfortable joking.

Song Changgui was so frightened that he almost knelt down to plead guilty, Yang Fei also hated her teeth itching, and hated her for not knowing herself......

However, Zhao Yin calmly raised his hand, took the umbrella that the guard held above his head, and handed it to Shi Yong.

In the astonishment of the crowd, he flicked his cloak and walked in front with his hands in his hands.

"Go home!"

……

It was the middle of the night when I came home from Shuishui Alley.

Shi Yong followed Song Changgui, looking for the traces of Da Hei all the way, just now the dog ran away by itself, Shi Yong was worried that it had no good place to go. Song Changgui saw that she was uneasy, so he suppressed the doubts in his heart, and only when he received the umbrella at the door of the house did he turn his head and cough heavily.

"I didn't teach you that."

Shi Yong frowned, looking dazed, "No?" ”

Song Changgui said: "No. ”

"No way. How could I have learned such skills if my father hadn't taught me? ”

Shi Yong tilted his head and made a look of trying to think, "It must be what Dad said when he was drunk, I don't remember." ”

Song Changgui has no other hobbies, he likes to eat a few glasses of wine, especially when he comes back from an errand, no matter how late it is, he can drink a few glasses of peanuts by himself.

Seeing that his daughter was serious, Song Changgui recalled for a moment, and it was also blurred, "However, my father doesn't know this, how can he tell you?" ”

Shi Yong pushed the door in and laughed, "Dad, maybe it's the ancestor's dream?" There are many strange things in this world, and horizontal and vertical is not a bad thing, and everyone will know that there is a great Song Qizuo in Shuntianfu, with a pair of discerning eyes, and he will cut off all the cases in the world, isn't it? ”

Song Changgui laughed when she praised her, and coughed again, "You girl, you have changed your personality recently, so good, very good." ”

Shi Yongwaner: "Then go and ask your daughter-in-law to wash your feet and go to bed early." ”

Wang was eavesdropping behind the door, his eyelids jumped, and he was so angry that he wanted to scold, when he heard Song Changgui say, "Ah Shi, why don't you ask me?" ”

Shi Yong said: "Ask what? ”

Song Changgui's brows were knotted, "What Xie said that day, you ...... Didn't you hear the heart? ”

Hearing him say this, combined with his reaction in the past two days, Shi Yong probably understood that she was really not Song Changgui's biological daughter.

"I hear you. You're my father, you're my father, why do you want to do so much. Dad, you're not sleepy, I'm sleepy. I went to sleep. ”

Seeing her smiling appearance, as if she really didn't go to her heart, Song Changgui breathed a long sigh of relief, and his heart fell.

Shi Yong turned around, Wang pushed the door out, glared at Song Changgui with white eyes, and went to the stove room with a snort.

Not only did he get hot water for Song Changgui, but Shi Yong was also fortunate to get a basin.

Wang knocked on the door and put the hot water bucket at the door, and reprimanded angrily, "Such a big girl, go to bed without washing your feet, what did the old lady make to raise you such a sloppy goods." Get up, wash and go back to sleep. ”

Shi Yong just changed her shoes, she took out the boots that had stepped on the rain and put them in front of Wang.

"I've been in bad health for the past two days, and I've had a lot of inconvenience. It's hard work. ”

Wang was so angry that he jumped up and went to get a broom, and Shi Yong carried water and went into the house to lock the door.

"Little hoof, this is crazy, so that the old lady is one by one."

……

Shi Yong didn't know what kind of pill Zhao Yin poured into her that day, but she felt that this menstrual affair was menacing, and her abdominal pain continued. She didn't go out for two days in a row, "lying on the corpse" on the bed, listening to Wang's scolding.

On the third day, she couldn't help it, so she packed up and went to the Good Medicine Hall to ask Sun Zhengye for peace, and by the way, let him take the pulse and prescribe it.

Sun Zhengye probed her pulse and was shocked, "Have you eaten the Asking Heart Pill?" ”

Shi Yong listened, "Master, do you know too?" ”

The master was caught off guard, and Sun Zhengye almost bit his tongue.

"Who is your master?"

"You." Shi Yong's face did not change, "Didn't you say that you should teach me medicine first, and then I will demonstrate acupuncture for you?" No denial is permitted. ”

Shi Yong was originally a studious person, and had systematically studied modern medicine, forensic science and trace identification, but in ancient times, when there were no high-tech instruments, there was little use of force. Now that she has a ready-made master, she naturally wants to learn.

Sun Zhengye was suspicious, "Why do you want to learn?" ”

"Don't you have a lot of skills." Shi Yong refused to let him take the topic away, "Master, what's going on with the Ask Heart Pill?" ”

"Well...... this"

Sun Zhengye's eyes flashed strangely, he forgot to refute Shi Yong's title, shook his head with his white beard, and said seriously: "This is an extremely precious medicine, also known as loyalty medicine, truth medicine, obedient medicine-"

------Off topic------

Note: The author is not good at physics, you can refer to the problem of mopping the floor at home, the light angle is different, the messy shoe prints on the ground are sometimes seen, sometimes they are invisible, and sometimes they are clearly dragged over, but they can still see the footprints. There is also the principle that when you look in the mirror, you can see the face clearly with the backlight, but you can't see clearly with the face light...... Well, that's about it.

Don't look into it, don't dig into it - the bar is yours.