Professor Shi's face remained expressionless. He had conducted this class over eighteen thousand times. Carefully, he strapped the old laborer's wrists and legs to prevent him from moving too much in pain later.

"Are you ready?" Professor Shi asked the old laborer again, his voice gentle. He sympathized with these people but had no choice but to use them to train his students.

"What?" the old laborer shouted back.

"Sigh!" Professor Shi sighed, knowing the old laborer was a bit hard of hearing. It wasn't because of old age but because the old laborer had damaged his inner ear nerves in a work accident last year.

"Are you ready?" Professor Shi had to raise his voice.

"I'm ready, go ahead! But... can the students go easy on me?" The old laborer pleaded pitifully, having been tormented by students during a previous practice session.

"Hmm, I'll try my best." Professor Shi told a white lie. He knew the students wouldn't listen to him. Besides, they were just students. If they could do everything perfectly, there would be no need for them to attend the vocational school.

After settling the old laborer, Professor Shi picked up the class list and adjusted his reading glasses.

"Today, we will practice the Hegu acupoint. We covered its exact location in the last class. Today's focus is on practical application. A few things to note during practice: first, the insertion should be gentle, without haste; second, make sure to locate the acupoint accurately, as improper needling will only increase the patient's suffering..."

"Enough with the long-winded speech. Let's get started! I'm ready to have some fun today," an impatient and slightly excited voice interrupted Professor Shi.

Hearing this voice, many students in the class stifled their laughter. Professor Shi lowered his glasses and looked through the gap above them, seeing the student who had spoken sitting in the back row with his legs up on the desk, looking like an old-fashioned landlord.

This student, Wang Lei, might not have a wealthy family, but his father was the deputy captain of the city police criminal investigation team. So, Wang Lei had grown up with numerous people "taking care" of him. At school, he was a notorious bully, and no one dared to provoke him.

It was said that a new student at the vocational school once accidentally stepped on Wang Lei's foot and shortly after took a half-month medical leave.

Professor Shi's gaze swept indifferently over Wang Lei's face without saying anything. The highly respected old professor wasn't afraid of Wang Lei but didn't want to engage with this spoiled scion.

"Chen Dake," Professor Shi began calling names one by one. When called, students would go to the podium to practice acupuncture.

Stolen story; please report.

The process was not complicated. Students would take out their needle packs, select a needle, and practice needling on the volunteer's acupoints. Acupuncture needles come in many types; historically, there were the nine classical needles, and in modern times, these have further diversified. The students generally used filiform needles for practice.

Filiform needles are very thin, with a diameter of about 0.3 millimeters. Even if inserted incorrectly, they wouldn't cause the volunteer too much pain. If they were to use thicker three-edged needles, the volunteers might flee or faint, turning practice into a potential crime.

Today's practice class proceeded much like previous ones. The old laborer sat in the chair, strapped at the wrists and ankles but still constantly twitching and grimacing in pain. He would occasionally cry out, sweat pouring down his face. Being a volunteer for this was a tough job.

"Shen Xingkong..." About halfway through the class, Professor Shi finally called Shen Xingkong's name.

Shen Xingkong was nearly asleep in class. He stood up only when he heard Professor Shi call him, yawning and slowly walking up to the podium.

Professor Shi was disappointed with these students. The ones who had gone before Shen Xingkong had no sense of proper needling techniques or accurate acupoint location. One student even aimed a needle at the old laborer's face, nearly causing him to wet his pants. Thankfully, Professor Shi intervened in time to prevent disaster.

The Hegu acupoint is located between the thumb and index finger on the hand, also known as the tiger's mouth, and is one of the acupoints on the Large Intestine Meridian of Hand-Yangming.

After stepping onto the podium, Shen Xingkong took out his needle pack, casually selected a longer filiform needle, and disinfected it with an alcohol swab.

"Hehe, Uncle, I'm sorry for what I'm about to do. If it hurts, just shout, and I'll stop," Shen Xingkong said, trying to be considerate.

"What did you say?" The old laborer couldn't hear clearly.

"Never mind!" Shen Xingkong shook his head, positioned the old laborer's right hand, and recalled the exact location of the Hegu acupoint as taught by Professor Shi.

Professor Shi seemed uninterested, just wanting the class to end soon so the old laborer could suffer less. Shen Xingkong wasn't known for his good grades, so when he started needling, the old laborer would surely scream in pain.

Professor Shi sighed inwardly, wondering what these pampered students had done to deserve such easy lives. Compared to them, the old laborer endured immense suffering for a few hundred yuan. Where was the fairness in this world?

"Ah..." As expected, as soon as Shen Xingkong's needle entered the old laborer's skin, the laborer screamed.

"Wrong point, withdraw the needle, next," Professor Shi ordered without even looking, telling Shen Xingkong to stop and leave.

But Shen Xingkong seemed not to hear Professor Shi. He remained kneeling in front of the old laborer, his hand lightly holding the needle, trembling slightly. His eyes widened, and his face looked as if he had seen a ghost.

Just now, as Shen Xingkong's needle accurately pierced the Hegu acupoint, he suddenly felt a surge of heat in his back, like a faucet being turned on. The heat traveled down his right arm to his fingertips, then through the needle into the old laborer's Hegu acupoint.

The sensation was bizarre, hard to describe in words. Shen Xingkong felt as though the old laborer's Hegu acupoint was drawing heat from his body. This heat, of unknown origin, made his spine burn and his right arm heat up, though it wasn't particularly uncomfortable.

"What are you doing? I said withdraw the needle," Professor Shi's voice grew stern.

"Hey, look at that old man..." Before Shen Xingkong could respond, Chang Le suddenly stood up in the classroom, pointing at the old laborer.

All eyes followed Chang Le's finger to the old laborer's face, noticing something strange. The laborer's expression wasn't one of pain but rather of someone soaking in a hot bath after days of exhaustion.

The old man's three thousand six hundred wrinkles had smoothed out, and his eyes had narrowed to slits.