Episode Summary
The investigation into Lu Wencai's murder begins, initially pointing towards Xie Xu when the suspected murder weapon bears his name. Xie Xu denies involvement and exposes Su Tangli's identity as a woman and disgraced official's daughter, accusing her instead. Su Tangli denies killing Lu Wencai. Lu Chang, Jian Mingshu, and others investigate, realizing the crime scene suggests a different killer. Using a clever soup trick, they expose Zhang Gongzi as the murderer, who confesses he killed Lu Wencai out of revenge for years of bullying. Zhang Gongzi later commits suicide in prison. A discovered doll suggests he might be Liu Yuanying's long-lost brother. Meanwhile, Xie Xu faces consequences for his actions, and Su Tangli's fate remains uncertain, though she is temporarily left at the Academy.
Spoiler Alert
Serendipity Episode 16 Recap & Spoilers: The Plot Thickens
So, the episode kicks off with a major investigation: Lu Wencai has been found dead under mysterious circumstances. His dad, Lu Shangshu (think high-ranking official), is absolutely devastated when he sees his son's body and immediately demands justice from Prince Rui and Prince Yu, who are on the scene.
The coroner gets to work and figures out Lu Wencai died pretty recently – within the time it takes for an incense stick to burn (that's quick!). They also find the murder weapon. When Prince Rui and Prince Yu examine it, they spot the character "Xie" carved on it. Uh oh. The only person at the Academy with that surname is Xie Xu.
Naturally, Xie Xu is the prime suspect. He insists the weapon was stolen from him a couple of days ago and swears he hasn't left his quarters since being confined. To back this up, he calls on Su Tangli, claiming she visited him just before Lu Wencai's estimated time of death. Here's where it gets juicy: Su Tangli totally denies it!
Backed into a corner, Xie Xu drops a bombshell. He reveals Su Tangli is actually a woman, the daughter of a disgraced official, no less! He claims she's manipulative and that Lu Wencai had discovered her secret. Xie Xu spins a tale saying he was influenced by her and got into a conflict with Lu Wencai because of it. Then, he points the finger straight at Su Tangli, accusing her of murdering Lu Wencai to silence him.
Su Tangli is absolutely heartbroken that Xie Xu would throw her under the bus like this just to save himself. They start accusing each other, basically tearing each other down in front of everyone. Prince Yu, meanwhile, is low-key enjoying the drama, probably because Xie Xu's backer (Yongqing Hou) is allied with his rival, Prince Rui. Politics, am I right?
Later, the ever-reliable Lu Chang checks in with Su Tangli. She firmly denies killing Lu Wencai. Lu Chang breathes a sigh of relief – as long as she didn't actually commit murder, there's still a chance to clear her name and sort things out.
Determined to find the real killer, Lu Chang teams up with Jian Mingshu, Song Qingzhao, and Ying Xun to investigate the crime scene. They quickly realize the initial setup is too obvious; neither Xie Xu nor Su Tangli would be that clumsy. After examining the body and scene (Song Qingzhao is surprised Lu Chang and Ying Xun are doing autopsy-like work!), they deduce Lu Wencai wasn't killed by the arrow/weapon found initially. It looks like someone snuck up and killed him from behind after he had already entered the location. This method doesn't fit Xie Xu or Su Tangli.
This means the real killer is still out there, and they probably have blood on their clothes. Ying Xun finds some poems Lu Wencai wrote, guessing he probably snuck in hoping to impress the princes with his poetry, only to walk into an ambush.
Now, how to find the killer with bloodstains they likely haven't had time to ditch? Lu Chang comes up with a clever, if slightly random, plan: serve everyone hot and spicy soup (Hu La Tang)! One student, Zhang Gongzi, adamantly refuses to drink it. Jian Mingshu then "accidentally" spills soup on him. When offered a change of clothes, Zhang Gongzi refuses again. Super suspicious! The final nail in the coffin comes when the authorities announce a break in the case and let everyone leave – Zhang Gongzi's relief and actions give him away.
Sure enough, they find bloodstains on Zhang Gongzi's inner clothes. Cornered, he confesses. His motive? Years of pent-up rage. He claims he studied diligently for a decade ("ten years of intense study) only to be constantly bullied and oppressed by Lu Wencai. He finally snapped.
With the real killer caught, the fallout begins. Zhang Gongzi faces justice. Xie Xu isn't off the hook either; he's in trouble for forging documents and harboring Su Tangli (who's technically considered a "criminal slave" due to her father's status). Prince Rui plans to report all of this. As for Su Tangli, Lu Shangshu (interestingly, the victim's father) suggests letting her stay at the Academy for now, under the Headmaster's watch. Before leaving, Prince Yu gives Lu Chang a look that seems loaded with hidden meaning. Hmm.
In palace-related side plots, Prince Rui returns home to find Yin Shujun has prepared soup for him. He's torn about whether to plead for leniency for Yongqing Hou (Xie Xu's family/backer). Yin Shujun offers some surprisingly sharp insights that genuinely impress the Prince.
Meanwhile, Jian Mingshu feels terrible. Even though the case is solved, she's upset about her earlier jealousy towards Su Tangli, especially now knowing her tragic backstory. Song Qingzhao steps in to comfort her (sweet!). Jian Mingshu tries to ask Zhang Gongzi if someone put him up to the murder as he's being led away, but he doesn't say anything.
But wait, there's one last tragic twist! Zhang Gongzi commits suicide in his cell by taking poison. While looking through his old belongings, Jian Mingshu finds a small doll that looks exactly like one belonging to Liu Yuanying. A sudden realization hits her: could Zhang Gongzi be the long-lost brother Liu Yuanying has been searching for? Just then, Lu Chang arrives with the news of Zhang Gongzi's suicide. Jian Mingshu quickly brings Liu Yuanying to the prison, but it's too late. Zhang Gongzi is barely alive, the poison already having done its fatal work.
