"Disease varies from person to person and from time to time. One must discern the details, then adjust the approach by adding or subtracting elements. Active learning and application are essential."

Doctor Ma nodded, his expression serious. "I've noted it down, Dean. I'll be sure to pay attention in the future."

Du Heng saw that Doctor Ma had paused, then continued, "Now let's discuss the second question: why use the Eight-Ingredient Rehmannia Decoction.

"Regarding this issue, you're likely unclear on two points. First, the headache is in the upper Jiao, while supplementing kidney water and fire occurs in the lower Jiao. So, why does treating the lower Jiao heal the upper Jiao?

"Second, rhizoma ligustici is a Yang medicine. How can it enter the most Yin of regions and still be effective?"

Doctor Ma's head bobbed like a small motor, nodding frantically. His greatest confusion lay with these two points.

Why did the patient have a headache? It was due to insufficient kidney water, compounded by overly vigorous and dry liver wood, leading to the upward flare of dragon thunder fire. Du Heng had explained this clearly during the syndrome differentiation, and Doctor Ma understood that part. But why use this particular medicine? That was what he couldn't figure out.

Now, hearing Du Heng address his concerns directly, he hurriedly picked up his pen and listened intently.

"Let's address the first question. Medical texts have long recorded that the brain marrow and kidney water are interconnected. After supplementing the kidney, kidney qi can directly enter the brain via the 'river cart' (referring to a person's kidneys, not the placenta), with no obstruction in between."

Du Heng noticed Doctor Ma had started writing again, so he paused for a moment. "As for the second question, although rhizoma ligustici is a Yang medicine, it can nourish blood and travel to the crown of the head. If it can reach the crown, why can't it enter the brain?

"Furthermore, with cinnamon added, it can support the life gate fire. Being of a similar nature, it harmonizes with the body's qi, enabling them to work in concert to dispel chronic conditions and entrenched afflictions.

"In this way, once the water and fire in the kidney are balanced, how could the dragon thunder fire possibly continue to surge into the brain? It will be compelled to stay where it belongs.

"Of course, after ten doses, rhizoma ligustici should no longer be used. This is because once the headache is cured, continuing to use it would consume the patient's vital energy, turning a benefit into a harm."

Doctor Ma looked at the notes in his hand and said sincerely to Du Heng, "Thank you, Dean."

Du Heng waved his hand. "As long as you understand, there's no need for thanks. We're colleagues here." Just as he was about to get up and leave, he stopped and added, "Actually, there's one more thing I should cover with you."

"Please go on, Dean. I'm listening."

"Once the patient has taken about ten doses and the headache has completely stopped, you need to replace rhizoma ligustici and cinnamon with white peony and angelica. This approach treats both the kidney and liver, ensuring the wood qi has no cause for dryness and the dragon thunder fire remains permanently contained within the kidney residence.

"This is the follow-up formula. The dosage should be reduced accordingly; it's best to proceed gradually and not aim for a quick fix."

Doctor Ma nodded, indicating he had noted it down.

Du Heng laughed. "After drinking so many doses of medicine, the patient is probably sick of it. Switching from a decoction to pills is also an option." With a wave of his hand, he walked out of the consultation room.

The first thing Du Heng did when he returned to his office was to call Wu Shengnan.

But after calling, just as for the past three days, she didn't pick up.

Du Heng got angry and sent a message directly: "If you don't answer your phone, I'm coming to your detachment to get you."

Less than thirty seconds after the message was sent, Du Heng's phone rang.

As soon as Du Heng picked it up, he yelled, "Wu Shengnan, are you taking this too far? Today is the fourth day! You don't answer calls, you don't reply to messages, you don't come home—what are you trying to do?

"If your phone hadn't still been reachable, if your brother hadn't said you were fine, and if no one had called me with a ransom demand, I would have definitely thought you'd been kidnapped."

Wu Shengnan on the other end of the phone listened quietly to Du Heng's tirade. After he finished, she whispered, "Honey, I was wrong. I won't do it again. I'm on a mission; it's not convenient for me to answer the phone."

Du Heng was still irritated. "Not convenient? It's been four days! You couldn't find a single moment to reply to my messages? Not even a split second to call me back?"

"I was afraid of worrying you."

"Your disappearing like a ghost is what's really worrying me, okay?"

"I know I was wrong. I'll never do it again."

"Come home tonight," Du Heng ordered, his anger subsiding slightly. After all, this was Wu Shengnan's job, and he could understand.

"UM..."

Hearing that, Du Heng's anger, which had just subsided, flared up again. "Wu Shengnan, what does that mean? You're not coming home tonight either?

"Fine, I'm going to your detachment right now to find out exactly what kind of assignment keeps an internal affairs officer away from home for four consecutive days without a single word."

"No, no, honey, don't be childish." Wu Shengnan quickly softened her tone. Once Du Heng stopped yelling, she said, "You know Zhang, right? Our detachment leader? He's suddenly gone deaf and has become dazed and unresponsive. On top of that, we're in the middle of tracking a stalker, so we really can't get away."

Zhang? Du Heng immediately recalled the dark-faced man from last year—a strong, masculine figure. How could he have become deaf and dazed?

"Was your Leader Zhang assaulted?" Du Heng's focus was peculiar; he showed no interest in the stalker but was very interested in Leader Zhang's condition.

"No, he wasn't assaulted," Wu Shengnan hurriedly explained. "We were on a mission together last Sunday. By morning, he couldn't hear anything. After a day in the hospital, his reactions started to slow down significantly.

"As of today, he's become somewhat dazed and unresponsive."

Wu Shengnan sighed again. "It never rains but it pours. Our Deputy Detachment Leader was transferred out this morning; he's gone to the local precinct to be their Deputy Chief.

"We're like unsupervised children now, completely at a loss."

Was this what Du Heng wanted to hear? Of course not.

So Du Heng asked, "Didn't the hospital diagnose what's wrong with your Leader Zhang?"

"They did. It's some kind of viral deafness."

"Did they say when he'll get better?"

"The doctor didn't give a specific timeframe, just said it would be a slow recovery process." Wu Shengnan's voice was also heavy with fatigue.

Du Heng was about to say more when he heard Wu Shengnan on the other end quickly say, "Honey, I'll call you back. Our detachment leader is calling."

With that, she hurriedly hung up.

Although Du Heng had yelled at Wu Shengnan, hearing the exhaustion in her voice made his heart ache for her.

But even if he felt for her, there was no way for him to show his concern now, for fear of disrupting her mission and causing some unforeseen accident.

This was also one of the reasons Du Heng didn't want Wu Shengnan to continue this job and strongly urged her to switch to internal work or another department.

Perhaps it was male chauvinism at work, but he truly didn't believe a woman could be a good criminal police officer, especially someone as impulsive as Wu Shengnan. However, this was her profession and her passion. Du Heng knew he couldn't use a heavy-handed approach to resolve this; he had to play the long game.

After sighing, Du Heng opened the file in front of him, but he found the words tasteless, his mind completely filled with images of Wu Shengnan.

Just like that, ten minutes passed. His phone rang again. Du Heng hurriedly answered, "Baby, what did your superior want from you?"

"Honey, I... I..." Wu Shengnan stammered, unable to get the words out.

Her stammering, however, instantly made Du Heng nervous. "Stop stammering and tell me! What's wrong? Did your superior send you on a business trip? Or are they transferring you?"

Du Heng guessed at both good and bad possibilities.

"My superior is transferring me," Wu Shengnan finally managed to say clearly.

"Transferred?" Du Heng was instantly overjoyed. This issue had troubled him for ages, and now, a transfer! "Which department? Is it strenuous? When you have a moment, help me arrange to meet your Captain Tao. I want to treat him to dinner."

Du Heng's joy didn't seem to affect Wu Shengnan. She continued timidly, "I didn't change departments."