"Xiao Guizi failed in protecting his master, drag him out and beat him to death..." In a fit of anger, Fourth Master turned his hand to kill Xiao Guizi.

Xiao Gui Zi turned pale with fright and clung to Consort Xi, crying and begging for mercy. Lan Qin stopped the guards and said to the Fourth Prince, "Yellow, Hongli's poisoning is really strange. Xiao Gui Zi was the only one who knew about it at the time. I hope to spare Xiao Gui Zi's life. Perhaps there will be some new discoveries..."

Upon hearing this, Xiao Guizi kowtowed frantically to Lanqin, blood instantly seeping from his forehead.

Lanqin squatted down and pulled Xiaoguizi aside, asking carefully, "Think again, is there anything you've forgotten?"

Xiao Guizi, panting, his eyes darting around, answered tremblingly, "This servant remembers... when we returned, only the Prince was there... This servant was wondering about it, so I asked the Prince..."

"What did Hongli say? Recall every single word he said to me..."

Xiao Guizi said, "The prince said he went to the Imperial Study but there was no teacher there, so he came back on his own... Oh, right! The prince also told us with a smile that the little eunuch who led the way had diarrhea and slipped away, so the prince went to the Imperial Study in the dark... We really don't know anything else..."

Lanqin seemed to grasp at a straw and said to the Fourth Master, "That's good. As long as we find the little eunuch who led the way that day, we'll know what happened."

Fourth Master helped Lanqin up and asked Xiao Guizi, "Think carefully, can you still tolerate the person from that day?"

Xiao Guizi replied blankly, "This servant doesn't recognize him. He's not from the Prince's quarters. There are so many eunuchs in the palace; this servant really can't remember who he is..."

Lanqin hurriedly grabbed Fourth Master and said, "Let's go ask the Master first. If the Master really went to find Hongli, he will know what happened..."

Fourth Prince patted Lanqin on the back, comforting her, "Don't worry, Hongli will be alright..."

The Fourth Prince immediately sent someone to invite the tutor from the Imperial Study to the Prince's residence. The tutor already knew that Hongli was unconscious, and seeing how sad and distressed Consort Xi was, he knew that the situation was not good, so he took the initiative to explain everything that had happened in the past few days.

The Fourth Prince impatiently interrupted him, asking, "I only want to know, a few nights ago, did you send someone to invite Hongli to the Imperial Study?"

The gentleman was greatly alarmed and knelt down, kowtowing: "Your Majesty, I did not send the prince to the Imperial Study at night, nor did I send anyone to invite him. Your Majesty's test is truly insightful..."

Lan Qin's heart sank, and she muttered to herself, "Someone must be spreading false information to lure Hongli out. Their scheme is aimed at Hongli alone; someone wants Hongli dead..."

The Fourth Prince had a bad feeling. He thought that once he ascended the throne, he could protect the people he loved, but he never expected that even as emperor, he would still be powerless. Seeing Lanqin heartbroken and helpless, he was filled with self-reproach: "It's all my negligence. Hongli's poisoning must have been premeditated. To do such a vicious thing right under my nose, I will definitely investigate to the end..."

Suddenly, the imperial physician exclaimed in surprise, and everyone crowded around. The physician carefully lifted Hongli's upper garment, pointed to a barely noticeable red dot, and said to the Fourth Prince and Lanqin, "Your Majesty, Consort Xi, please take a look. This humble servant has suddenly discovered this inexplicable needle mark on the Prince's body! This humble servant believes that the Prince's poisoning may be related to this needle mark..."

Lanqin was startled. Upon closer inspection, she realized it was indeed a needle prick that wouldn't be noticeable unless you looked very closely.