Prince Lu’s “secret garden” was known only to him alone.

Behind the bookshelf in his study was a hidden chamber. When Prince Lu’s palace was originally designed, the Ministry of Works created this secret room to store confidential documents and Prince Lu’s册封 certificate and gold seal.

But what had Prince Lu put here? Various erotic novels and lewd songs, plus some角先生, little bells, and other vulgar items.

Nine years later, he was still the same Prince Lu, still with the same sleazy taste.

Seeing these worldly things, Hu Shanwei immediately forgot her fear of the “deadly poisoned corpse” in the ice cellar.

The underground passage was beneath the floorboards under a box of erotic items. Lighting candles and descending the stairs, there was actually natural light inside, making illumination unnecessary.

It turned out this underground chamber had one wall embedded with large transparent crystal stones connecting to the koi pond outside the study. Sunlight passing through the double refraction of water surface and crystal stones made the entire underground chamber seem to sway with the water waves – dreamlike and fantastical without needing to take drugs.

In the center of the underground chamber stood a bronze tripod. Underground was a half-burned furnace using fire-resistant coal blocks. The furnace’s smoke pipe was a thick round iron tube directly connected to the study’s underfloor heating system, integrated with the palace’s heating facilities. No wonder it had gone undetected for nine years of burning.

A bookshelf displayed bottles and jars of Five Stone Powder ingredient formulas in various colors – stones and plant-based medicinal materials whose names Hu Shanwei couldn’t identify – plus various grinding and cutting tools, even an extremely sensitive Western small balance scale for weighing.

Ru Siyao took out a stick-shaped pale yellow mineral from an iron container. The moment she struck it with an iron hammer, a strange odor emerged. “Smell this – what does it smell like?”

Hu Shanwei boldly leaned over to smell it. “Garlic – like eating dumplings with garlic and vinegar sauce, then talking to people without rinsing your mouth.”

Ru Siyao returned the mineral to its place. “This is the realgar that Shen Qionglian sought at medicine shops – the main source of arsenic. When struck with iron tools, it emits a garlic stench.”

Hu Shanwei quickly pulled out her handkerchief, ignoring her elegant court lady image to pick at her nostrils… fearing she’d inhaled realgar powder.

“Don’t worry, this amount won’t harm your body.” Ru Siyao wrote a note and stuck it on the iron container as a label. “Actually, realgar is an expensive medicinal ingredient. With proper formulation, it can heal flesh and save people from illness. If used wrongly, it harms people – that’s human disaster, but realgar itself is innocent.”

Despite these words, Hu Shanwei still shook out the handkerchief she’d used to wipe her nostrils, fearing residue remained, saying sheepishly: “Like striking it with iron tools produces that garlic stench. Striking with wood wouldn’t produce such nauseating odor? Realgar itself isn’t wrong – it just meets the wrong people using it wrong.”

Ru Siyao said seriously: “Striking with tin or copper tools also wouldn’t produce such stench. Things similar to realgar include cockroaches, especially the big flying cockroaches from Yunnan. Though they seem disgusting and filthy, if you cultivate their eggs in clean places and carefully feed them, mature big cockroaches dried and ground to powder have miraculous effects treating stomach ulcers, mouth ulcers, and other internal organ damage.”

Hu Shanwei felt her stomach contents rising: Please stop talking – I was just making an analogy, not overreaching to discuss medicine with you…

Ru Siyao weighed all the realgar she could find in the underground chamber on the Western balance, recording the weight.

Hu Shanwei asked: “Is this realgar enough for a lethal dose?”

Ru Siyao said: “Depends on the realgar’s quality. I’ll randomly select five pieces of similar weight, grind them to powder, refine them, remove impurities, and extract arsenic.”

“From visual inspection, this grade of material probably can’t kill anyone, though it depends on the person…”

When discussing medicine, Ru Siyao simply couldn’t stop talking. In a blue and white porcelain garlic-bulb vase on the bookshelf, Hu Shanwei found five pills of the same Five Stone Powder that had transformed Prince Lu the Absurd from a deadly poison master into a deadly poisoned corpse.

Five thumb-sized red beads arranged on pure white silk handkerchief created a strange beauty.

Hu Shanwei asked: “How long does extracting arsenic from these take?”

Ru Siyao cut open half a pill with a small knife, crushed it, smelled it, even used her tongue to “taste” a tiny bit of powder, then rinsed her mouth and took an antidote pill before saying:

“Very troublesome. The technology for extracting arsenic from realgar is quite mature – I can just borrow various furnaces and tools from a large medicine shop. But this pill contains at least a dozen medicinal ingredients plus five types of stone powders. Separating them one by one – even expert pharmacologists might not manage it.”

Hu Shanwei got a headache: “Then how do we confirm Prince Lu the Absurd died from arsenic in the pills rather than other poisoning?”

Ru Siyao said: “There’s a fastest method – find a pig about Prince Lu the Absurd’s weight, mix the pills into feed and see if the pig dies. Pigs’ internal organ structure resembles humans’.”

Pig: Though death comes sooner or later, I choose dying under a butcher’s knife – at least it’s quick.

Hu Shanwei said: “These are the last five pills – eating them destroys the evidence.”

Ru Siyao wrapped the pills in waterproof oiled paper. “In that case, I’ll work harder and stay up all night to extract the arsenic.”

Hu Shanwei said: “Didn’t you just say even expert pharmacologists might not manage it?”

Ru Siyao said calmly: “I’m an expert among experts.”

Hu Shanwei saw hope again. Asking Ru Siyao for help was indeed right. One person can’t clap – she couldn’t complete this task alone. Having worked as a court lady in the palace for twelve years, befriending various talented women and building trust and understanding – these were her invisible wealth.

Ru Siyao was meticulous, even scraping residual pill dregs from the bronze tripod and coal ash from outside the pot bottom, collecting everything in paper packages methodically. Hu Shanwei could only assist.

“Screech screech!”

Ru Siyao scraped the pot bottom, producing harsh sounds. Hu Shanwei felt the grating noise entering her ears like scraping her heart – unbearable. She noticed a stack of books on the bookshelf that appeared to be sage texts from their covers.

But knowing Prince Lu the Absurd’s consistent nature, they surely contained erotic novels or pictures inside. That’s why neither had opened these sage texts while in the underground chamber.

But now the pot-scraping noise was too irritating. Hu Shanwei urgently needed distraction. Anyway, they’d searched even coal dregs in the underground chamber – only these books remained unchecked.

Preparing herself mentally, Hu Shanwei opened a sage text cover to find neat, elegant handwriting – it was “Pill-Refining Notes” disguised as sage texts. Prince Lu the Absurd had detailed records of every pill-refining session, including various medicinal ingredients’ names, weights, ratios, and so forth.

Besides this, he also recorded results after taking medicine: some provided ethereal feelings, some caused vomiting and diarrhea, some had no effect, some were just black charcoal impossible to swallow, and some even included detailed records of “serving three women in one night” while maintaining stamina after taking them.

From recorded dates, Prince Lu the Absurd refined pills about once monthly, producing roughly ten pills each time. Each session adjusted formula ratios and fire timing based on past experience. Earlier years often produced discarded pills, but recent years showed fewer mistakes as his pill-refining skills became increasingly proficient, regularly achieving “immortality.”

The records were neat and meticulous, more careful than Ru Siyao writing “Corpse Records.” Clearly Prince Lu the Absurd wasn’t without strengths – they were just all in crooked paths. If he’d applied this conscientiousness properly, like Fifth Prince Zhou Prince Zhu Su’s dedicated medical research and medical text compilation, perhaps Prince Lu the Absurd wouldn’t have died so absurdly and might have achieved something else.

Hu Shanwei felt sorry for Prince Lu the Absurd, handing the unexpected discovery “Pill-Refining Notes” to Ru Siyao.

Flipping through it, Ru Siyao’s eyes immediately brightened. “This is good – all formulas clearly recorded. Quickly find his most recent pill formula.”

Following dates, Hu Shanwei found the deadly pill’s formula.

Looking at the realgar dosage, Ru Siyao frowned. “Wrong. From the amount, unless the realgar’s arsenic content reaches thirty percent, five pills are far from lethal dose.”

Hu Shanwei quickly brought over the iron container with realgar. “See if these reach thirty percent?”

Ru Siyao shook her head. “Impossible. Realgar’s main components are iron, sulfur, copper, etc. Arsenic reaching ten percent would be very high purity, not to mention the formula includes several detoxifying medicines. Also…”

Ru Siyao quickly flipped through each experimental formula, using red ink to circle realgar amounts. “Through personal consumption, Prince Lu the Absurd understood realgar’s terrible toxicity, so his realgar usage in formulas decreased over the years while health and aphrodisiac ingredients increased. Look at this formula when he recorded serving three women in one night – self-taught, he created a formula similar to brothel red pills.”

Ru Siyao flipped rapidly with good memory, stopping suddenly. “Six months later, he used the same formula to refine another batch.”

Prince Lu the Absurd was actually a pill-refining genius! Good at criticism and self-criticism, using himself as guinea pig for experiments, not harming others or small animals, gradually improving formulas according to his needs.

Hu Shanwei didn’t know how to evaluate this deadly poisoned corpse, saying: “Since Prince Lu understood pharmacology and was wary of realgar, why did he still fall victim to it? Could it be intentional poisoning?”

Ru Siyao wouldn’t conclude definitively: “Most drowning victims can swim, most people losing their fortunes were once wealthy – such things are hard to say. I need to test the pills’ toxicity first.”

After examining the corpse and searching the underground pill-refining chamber, when they emerged from the underground chamber, night had fallen. Haitang stood guard outside, boredly roasting taro in a brazier.

Smelling food’s aroma, their stomachs rumbled like drums. To save time, neither had eaten lunch. Haitang peeled roasted taro for them, opening just a slit to eat with small silver spoons.

Blowing on the soft taro paste, Hu Shanwei asked: “Did the Crown Prince send anyone to check the pill-refining chamber?”

“I stayed vigilant with lookouts around the study area, but no one came this way,” Haitang said. “Ministry of Rites personnel have re-prepared Prince Lu the Absurd’s remains, dressed in imperially bestowed python robes. Because his death appearance was too horrible with eyeballs nearly flowing out, Vice Minister of Rites Huang Zicheng suggested covering his head with a golden mask, which the Crown Prince approved…”

While they ate roasted taro, Haitang reported the day’s funeral progress at Prince Lu’s palace:

Ministry of Works personnel, following the Crown Prince’s orders, went to the suburbs to read feng shui and select tomb sites. Finding nothing suitable in Yanzhou territory, they planned to check neighboring Zoucheng tomorrow.

The deadly poisoned corpse wearing a golden mask was moved to the newly established mourning hall. The fifty-sixth generation Duke Yansheng Kong Nayen from Qufu’s Kong family mansion had come to pay respects to Prince Lu the Absurd, personally received by the Crown Prince.

Officials from various Shandong locations plus cultural celebrities submitted name cards. Huang Zicheng drafted the mourning order list – names called entered to offer incense and pay respects, then seated. Today’s scene was busy but orderly, everyone praising the Crown Prince’s virtue in maintaining the situation.

Princess Lu barely managed outside funeral affairs, relying entirely on the Crown Prince, staying constantly with the wet nurse beside one-month-old Guo’er. However, Princess Lu strictly managed the palace’s inner quarters, with stewardess grannies patrolling everywhere day and night. The pill-refining chamber, located in the inner study within the inner quarters, remained tight as an iron barrel regardless of outside commotion.

“No wonder Ru Siyao and I had peace and quiet in the pill-refining chamber all afternoon without disturbance,” Hu Shanwei said. “That was Princess Lu’s achievement.”

Haitang also praised: “Imperial Consort Guo chose a good daughter-in-law – pity Prince Lu had no fortune to appreciate her.”

Hu Shanwei said: “Go tell Princess Lu that Ru Siyao and I need to disguise ourselves and leave the palace tonight to test pills at medicine shops. No one can discover what we’re doing or our whereabouts – have her arrange it. Also delay things outside – we might return late tomorrow and no one must know we went out.”

Princess Lu had them loaded into an empty milk cart to leave the palace, not asking what they’d discovered, seemingly uninterested in Prince Lu’s death, single-mindedly focused on raising Guo’er.

They came to the Shen family medicine shop where Shen Qionglian also had discoveries. Today she’d shown Prince Lu’s portrait to various medicine shop clerks, asking if they’d seen this person.

Since princes couldn’t leave their fiefs without imperial summons – otherwise it was the capital crime of rebellion – Prince Lu had to purchase all pill-refining minerals and medicinal materials from local Yanzhou medicine shops, impossible to step half a pace outside Yanzhou city.

So when Shen Qionglian displayed the portrait, clerks immediately recognized him:

“Isn’t this the little painter who bought realgar from medicine shops for mice? He said mice at home liked paste’s taste, always gnawing painting paper, making his studio messy with heavy losses. He regularly mixed realgar powder into paste to poison batches – they’d quiet down for a while. He came several times yearly, but he looked quite handsome, refined, and spoke politely, so I remembered him.”

“When he bought realgar at our shop, he called himself a poor scholar – similar excuse.”

“I also know him. He called himself a wandering doctor making a living. At our shop he bought medicines that wouldn’t kill or cure people, but never bought realgar from our shop…”

From clerks’ descriptions, Prince Lu the Absurd was very cautious about this, purchasing formula ingredients from different shops under different identities, putting almost all his wisdom into pill-refining.

Moreover, Prince Lu the Absurd absolutely handled pill-refining personally, trusting no one else. So no matter how vigilant Princess Lu was, she never imagined having a deadly poison master in her own underground chamber.

Realgar was special merchandise at medicine shops. How much came in, how much sold, who bought it – all required registration and periodic submission to authorities for review. If numbers seemed abnormal, authorities investigated. To transfer risk, medicine shops required buyers to sign, seal, and leave handprints – otherwise they’d rather not sell than risk lawsuits.

To confirm it was Prince Lu the Absurd himself, Shen Qionglian pulled out realgar purchase registration records. With amazing memory for handwriting and handprints, using a Western magnifying glass for comparison, she separately listed all of Prince Lu the Absurd’s realgar records over nine years, including purchase dates and weights.

When Hu Shanwei and Ru Siyao found her at the medicine shop, she’d just finished writing.

Looking at Shen Qionglian’s statistical records, Ru Siyao kept shaking her head. “If all this realgar was consumed at once, it could poison Prince Lu the Absurd to death nine more times.”

Shen Qionglian asked: “So it really was Prince Lu the Absurd’s own fault?”

Ru Siyao still shook her head. “The key is quantity. Never mind eating realgar powder – even eating equivalent amounts of lime, cinnabar, malachite, or even gold would kill him three or four times.”

Hu Shanwei showed Shen Qionglian Prince Lu’s “Pill-Refining Notes.” “From his formula records each time, Prince Lu the Absurd had long been wary of realgar, consistently reducing amounts, even gradually adding some detoxifying medicines to neutralize realgar’s toxicity. This past year, after each pill consumption, he swallowed five raw egg whites and drank milk frantically – self-taught methods to reduce stomach and intestinal burning sensations, also helping detoxification. He might have died around forty from accumulated toxins, but being so careful yet dying in his early twenties – Ru Siyao also finds this suspicious.”

Ru Siyao took out the red pills. “Let me borrow your shop’s medicine-making tools to test whether these things killed Prince Lu the Absurd.”