Song Mu stood beside the water dispenser, turned around, and looked at Wang Shen from a distance, a casual smile still on his face. "Officer Wang really knows how to joke."

“I’m not joking with you. The so-called patient research data from last night is all fake. You went to that bar and most likely found me there. Believe me, I have plenty of evidence to prove this.” Wang Shen didn’t respond to Song Mu with a smile; his expression became even more serious.

"You forgot? I have an alibi. My secretary is my best witness." Song Mu didn't move, remaining standing next to the water dispenser, taking a sip of water from his cup.

"I've heard that some people drink more water when they're nervous. It's said that drinking water helps relieve tension. Dr. Song, is there really such a claim in your field of psychology?" Wang Shen stared at the water glass in Song Mu's hand, his tone indifferent as he made a digression. Song Mu's hand holding the glass visibly trembled, and he fell into a brief silence.

“Some people are, and some people aren’t.” Song Mu took his water glass back to his desk and sat down in his chair.

"So, is Dr. Song one of those people, or someone else?" Wang Shen didn't pay attention to Song Mu's expression this time. "As for your so-called alibi, it's easily overturned. The game you're playing, many people played it back in their student days. At that time, we called it 'dummy trick'."

Song Mu narrowed his eyes slightly, a hint of coldness and doubt flashing in them. Wang Shen looked up and met Song Mu's gaze. Seeing that Song Mu didn't intend to speak, he continued, "You're probably thinking that all of this is just my guess. Well, that's true. However, when I first arrived, I spoke with your secretary and discovered that you don't allow your secretary to enter your consultation room casually. The consultation room is separated from the lobby by frosted glass. During the day, it's not noticeable, but at night, when the lights are on in the consultation room, anyone in the room will create a blurry silhouette, right? You just need to prepare a tool similar in size to yourself—maybe a large stuffed animal or something else. In short, just let your secretary see a blurry outline of you sitting at your desk. That way, a perfect alibi is created."

“Officer Wang, if there’s anything about you that I admire, it’s your amazing imagination.” Song Mu smiled and shook his head. He was about to pick up his water glass again, but after moving his fingers, he gave up the idea. “My secretary saw me enter the office, and I didn’t leave during that time. You can verify that with her immediately.”

“Don’t you think that statement exposes your problem?” Wang Shen chuckled and shook his head. “According to your secretary, you’ve been in the office since morning. If you haven’t left the office at all, then…” Wang Shen paused, looking at Song Mu meaningfully. “So how do you handle your personal problems? I looked around this consultation room, and it doesn’t seem to have a restroom. You’re not going to tell me you use plastic bottles, are you?” Wang Shen joked, but Song Mu didn’t find it funny at all.

"This is a matter of my personal privacy, so Officer Wang need not worry about it. It is a fact that my secretary saw me enter the office, and it is also a fact that I did not leave the office. These two points are enough to prove that I did not go to that bar last night."

“It’s very likely that the secretary saw you enter the office. But it’s hypothetical that you didn’t leave the office.” Wang Shen shook his head again, rejecting Song Mu’s explanation.

"Do you think I can turn into a fly and fly away?"

"You certainly can't turn into a fly and fly away, and I know you don't have that ability. Otherwise, I would have had a zoologist come with me today. However, although your counseling room has a toilet, it's outside in the lobby. You can endure not needing to use the toilet all night, but your secretary can't. While your secretary gets up to use the toilet, you can quickly set up the dummy and leave the counseling room. Now that I think about it, it really was a perfect plan. Moreover, I've observed the structure of this building; there are only surveillance cameras in the elevators, not in the stairwells. You can avoid the cameras by going down the stairs; it's all truly undetectable."

"In the end, all of this is just your speculation." Song Mu stared at Wang Shen and chuckled, his expression remaining unchanged.

“Once you leave this building, there will be surveillance cameras on the street that should be able to capture people coming and going. Of course, you are very clever and will definitely disguise yourself in various ways so that our police cannot identify you.”

"Since your police force cannot identify me, please wait until you have concrete evidence before you say these things to me." Song Mu's emotions began to fluctuate, and his tone became less gentle.

Wang Shen shifted his gaze from Song Mu's face, a smug look gradually appearing on his own. He picked up his paper cup, walked to the water dispenser, and turned it on. Once again, only the gentle sound of water hitting the bottom of the cup filled the consultation room. Wang Shen poured himself a glass of water, mimicking Song Mu's gesture, took a sip, and looked at Song Mu, saying, "Dr. Song, please don't rush. Let me explain the case first."

After speaking, Wang Shen finished the water he had just poured in one gulp and then threw the paper cup into the trash can next to the water dispenser. "Liang Li was killed with a single stab wound. The weapon was probably a short knife, and the attack site was her chest. From this perspective, the murderer was relatively merciful. At least, Liang Li didn't suffer too much pain before she died. This foolish woman probably thought the murderer was going to rob her, so she probably gave him all her money before she died. Unfortunately, the murderer didn't care about the money at all, but it's this money that left us with very good evidence. Dr. Song, would you like to know what valuable clues this money left us?" As Wang Shen spoke, he walked towards Song Mu's desk, looking at Song Mu with an admiring expression in his eyes.

Song Mu's brows were already quite furrowed. He stared at Wang Shen, his hands clasped tightly together.

“You probably know how alleyways are; the roads aren’t always very clean. During the day, vendors often spill dirty water on the ground. Coincidentally, there was still some dirty water on the ground that night. The murderer probably didn’t notice the dirty water, so he stepped on the banknote. That’s how the clear pattern of the murderer’s shoe sole was left on the banknote.”

After Wang Shen finished recounting this scene, Song Mu frowned even more deeply and lowered her head slightly to avoid eye contact with Wang Shen.

“Originally, with so many complicated patterns on the soles of the shoes, we had no idea where to begin. But this murderer is just too rich…” Wang Shen walked to the other side of the desk, his eyes fixed on Song Mu.