Cyanide

Lore & Background

In the pharmacological tradition of the Empire, cyanogenic glycosides are catalogued alongside the more 'noble' venoms—aristolochic acid, aconitine, atropine—but they occupy a peculiar limbo. They are not exotic imports from distant lands; they are native, common, found in the pits of orchard fruits, in the sprouts of grain, in the leaves of ornamental shrubs lining the palace gardens. This ubiquity makes them the poison of choice for an assassin who wishes to leave no trace of foreign trade, no suspicious shipment, no exotic ingredient to implicate a rival. The poison is already in the walls, in the soil, in the very air of a room where a bitter-almond pit has been crushed between two stones and left to release its invisible vapor.

Maomao's relationship with the cyanide family is one of intimate, almost tender familiarity. She can identify the specific glycoside—amygdalin, linamarin, dhurrin—by the subtle differences in odor, by the pH of the gastric residue, by the particular shade of cherry-red that the victim's venous blood takes on when it can no longer release oxygen to the tissues. Her treatment protocol, refined through years of slave-labor experimentation and palace pharmacy practice, is a delicate dance: first induce a controlled methemoglobinemia with a nitrite salt so that the hemoglobin is 'occupied' and can no longer bind free cyanide; then flood the body with a sulfur-donor (thiosulfate) so that the cyanide is converted to the far less toxic thiocyanate and excreted in the urine.

The timing must be precise. Too early, and the nitrite itself becomes lethal. Too late, and the cellular respiration cascade has already cascaded into irreversible organ failure.

The psychological weight of a cyanide case in the palace is heavy. Because the toxin is so fast, the victim often dies before the poisoner has even set down their cup. Witnesses describe a sudden clenching of the jaw, a brightening of the cheeks, a single gasp. There is no prolonged agony, no days of wasting. There is only the before and the after, and Maomao standing between them with her mortar, her pestle, and her unflinching eyes, trying to pull a soul back from the edge of a silence that was supposed to be permanent.

Reader's Guide

In-world name: Bitter-Almond Venom (苦杏毒) / Prussic Compound family.

Botanical origin: Amygdalin-rich seeds from the palace orchard's bitter-almond and wild-cherry trees; also found in the sprouts of certain grain cultivations and the leaves of ornamental shrubs in the Western Garden. The glycoside is non-toxic until hydrolyzed by gastric acid or enzymatic breakdown, releasing free hydrogen cyanide.

Preparation & concealment: Most commonly, a single pit is crushed between flat stones or in a mortar, then the residue is dissolved in tea, wine, or a sweet syrup. In gaseous form, a small quantity of a cyanide salt (e.g., ferrocyanide) is heated in a brazier or dropped into an acidic solution, releasing HCN vapor into a sealed room. In confectionery, the glycoside is suspended in a sugar glaze so it survives the stomach's transit long enough to hydrolyze.

Symptom timeline: Onset 1–15 min (ingestion) or 30 sec–2 min (inhalation). Early: headache, dizziness, tachycardia, nausea, a faint cherry-blossom flush on the cheeks. Peak (3–7 min): respiratory distress, muscle rigidity, loss of consciousness, venous blood turning bright arterial-red. Terminal (10–20 min): cardiac arrest, cerebral hypoxia, death. Inhalation of high concentrations can compress this to under 60 seconds.

Maomao's antidote protocol: (1) Immediate nitrite administration (amyl nitrite inhalation or sodium nitrite IV-equivalent) to induce methemoglobinemia and sequester free cyanide. (2) Sodium thiosulfate infusion to activate the rhodanese pathway, converting cyanide to thiocyanate for renal excretion. (3) Supportive ventilation; removal from contaminated air; gastric lavage if ingestion is recent. She emphasizes that the nitrite dose must be titrated—excess methemoglobinemia is itself fatal.

Arcs: Cyanide-family toxins recur as a detection-and-treatment benchmark across multiple poisoning cases, serving as a 'speed test' for Maomao's diagnostic instincts. It is a recurring tool rather than a one-off, appearing in both liquid and gaseous forms in different settings.

Recurring vs. one-off: RECURRING. The cyanide family is one of the most frequently encountered toxin classes in the series, used to test Maomao under time pressure and to highlight the gap between a poison's simplicity and the complexity of saving a life from it.