Thanks to Raiseth (on SV), Flashkannon (on SV), and Volossya (on AO3) for beta-reading this chapter for me.

I try to reply to every comment I get, but it is difficult for me to do that with guest reviews. Therefore, in reply to the comments I have received since I posted the last chapter, I'll just say that this fic is a crossover because it combines the settings of AsoIaF and My Next Life as a Villainess and uses characters from both, I agree that Katarina Claes in this fic seems to be smarter and less cruel than Cersei Lannister, and I'd like to thank littlestar for giving me such a lovely and encouraging review. That cheered me up considerably, so thank you!

The Expert Poisoner

The upstairs room in which Katarina regularly took lessons from Maester Pycelle was pleasant and airy, with a commanding view of the grounds surrounding the manor, and on clear days had sunlight streaming in through the windows. She had her own desk, which was well-stocked with goose-quill pens, a bottle of ink, and a stack of paper, as well as a piece of slate and some chalk that she used for note-taking. Because Sienna had been staying with the Claes family for an extended period of time, there had been a desk especially set up for her as well.

When the two girls entered the room, they found Pycelle waiting for them. Standing by his own desk upon which there was a pile of books, papers, and various writing implements, he was a stooped old man with a balding pate and a long white beard. He wore a heavy chain made from an assortment of different metals, signifying the subjects and topics of study that he was deemed to have mastered; it wrapped around him twice, stretching from his left shoulder to underneath his right arm.

As Katarina and Sienna sat down at their usual desks, the maester glanced at them and then at the clock on the mantelpiece, unable to fully conceal his irritation at their lateness. Putting on what he must have thought was a genial, avuncular smile, he said, "So good of you to join me." Only the barest trace of sardonic disapproval could be detected in his voice.

"I am sorry that we're late," said Katarina, bowing her head. "My father asked to speak with us immediately after breakfast. We've been in his study, talking to him, until now."

"I'm sure you had good reason to do so," said Pycelle in an ingratiating tone. "Now, I hope that you are ready for this morning's lesson and that there will be no further delays."

"Actually… I know that we were meant to be studying arithmetic, but I think – and my father agrees – that there is something more important we need to learn from you," said Katarina. "Have you heard what happened to us yesterday?"

"Yes, you got into a great deal of trouble and had to be rescued from a pack of hungry wolves by a band of scruffy mercenaries," said Pycelle. "But I don't see what that has to do with today's lesson."

"Well, before that, Sienna and I went into town to visit a witch who was supposed to be able to tell the future. Her name was Maggy the Frog. You may have heard of her. She gave each of us a prophecy, saying that we were going to die soon. Perhaps we would have been all right if we had never spoken to her – perhaps she put a curse on each of us – I don't know."

"Preposterous. She was a charlatan, no doubt."

"No, she wasn't," said Katarina, shaking her head. "Her predictions seem to be coming true. Already, I've had to save Sienna's life several times. On the way home, I had to save her from falling down an old well, being trampled by a horse, being crushed under a pile of cabbages – and, after our carriage broke down, I had to save her from being shot dead by a group of bandits. This morning, at breakfast, my father had to save her from choking to death. I'm worried about what might happen next."

Pycelle's skeptical look turned into a disgusted sneer. "Filthy foreign magic. It shouldn't be allowed," he muttered. "But I don't see how I can help. I have many areas of expertise, but magic is not one of them."

For a moment, Katarina wanted to smugly point out that the elemental magic that many of Sorcier's nobles possessed was originally foreign: the Targaryens had brought it with them when they launched their campaign of conquest, several centuries ago. However, she understood that annoying Pycelle in this way would be counterproductive. She needed his help; therefore, it would be wise to stay on his good side.

"This morning, when I saw Sienna choking to death, I was utterly helpless. I didn't know what to do," she said. "I can grab her to keep her from falling, or I can pull her out of the way of something that would stab or crush her, but I can't do anything to save her from threats that I know nothing about. That's when I thought about poisons. Fortunately, she hadn't been poisoned – it was just a chunk of apple that had got stuck in her throat – but isn't there a poison that does something similar?"

"The strangler, yes. It causes the throat to clench tighter than a fist, causing suffocation, and has no known antidote. An expensive poison for those who want to make absolutely certain that their victims will die from it," said Pycelle with a thin smile. "Don't worry, though: unless your little friend has made some very wealthy and influential enemies, I can assure you that no one would spend so much money to guarantee her death."

"Accidents can happen," said Katarina, her agitated mind imagining a possible scenario in which Sienna stumbled upon an attempt to assassinate someone else and was poisoned by mistake. "And anyway, there are plenty of other poisons, aren't there? That's what we need you to tell us about. How can we protect ourselves from being poisoned? What precautions should we take? In general, I mean."

The maester hesitated. "Although I agree with you that this is valuable and potentially useful knowledge, I think that I should confirm with your father that this is something he is willing for you to learn."

"If you must. I've already spoken to him about it, so I'm sure he'll tell you that it's fine."

"Nevertheless, I must check," said Pycelle, turning away and shuffling out of the room.

He was gone for several minutes. During that time, the two girls sat in uneasy silence until Sienna said, at last, "I appreciate your doing so much to help me."

"I'm not exactly being unselfish," said Katarina with a feeble grin. "If you die, Maggy's prophecy will have come true, making it more likely that I will die as well. So, because I want to live, I'm going to keep you alive for as long as I possibly can."

"Well, thank you," said Sienna. "You're a good friend."

Katarina gave an embarrassed shrug and was relieved when Pycelle re-entered the room. He was carrying two leather-bound books under one arm. There was what appeared to be a genuine smile on his face and his movements had an excited energy that had not been there before: evidently, he was glad of this opportunity to lecture on a subject that he knew well and was enthusiastic about.

Adding the books to the pile on his desk, he took a few deep breaths, turned to look at the two girls, and said, "I am sure that many of my fellow maesters would be appalled if they heard that I had given you accurate information about poisons. From their point of view, this knowledge is too dangerous: it has too much potential for misuse and too much capacity to cause harm. They would say that you are too young and too female to be trusted with it. However–" He gave Katarina a significant glance. "–your father says otherwise. He believes that you can be trusted with this information. Moreover, he thinks that it may be essential for you to know, in order for you to survive."

There was a pause. Katarina felt a surge of gratitude towards her father for his faith in her.

"All knowledge is valuable, even if it is unpleasant," said Pycelle, gazing off into the distance. "Even if what I am about to tell you could be used for evil, that doesn't mean that there is no possibility of it being used for good. It is my hope that you will use this information to protect yourselves and others. In a decade's time, you will be young women: by then, you may already be married and have young children of your own."

"That seems unlikely," said Sienna, looking dubious.

"Do you really think so? When you are nineteen years old, prime marriageable age, I will be surprised if you haven't been married off already," said Pycelle. "Even if you can't inherit, you will undoubtedly marry a man of substance and he will need an heir as soon as possible." Again, he glanced at Katarina. "By all accounts, King Robert loves his sons, but that doesn't mean that he won't use them as bargaining pieces. As a way of binding his kingdom closer to him, he has offered to marry his sons to the daughters of four of the most powerful families in Sorcier. He will want to secure his marriage alliances as soon as possible. At the very latest, you will be married to Prince Jeord by the time you are eighteen."

I'm going to die before I'm eighteen, Katarina realized, suddenly overcome with horror and panic. That's what Maggy the Frog meant. Jeord will reject me in favour of another woman, who will be as pure, and sweet, and beautiful as a flower in springtime, and then he will kill me.

She heard a chair scrape sideways across the floor. Noticing her distress, Sienna had moved closer to her and was offering her a hand. She took it gratefully. They gazed into each other's eyes, sharing a moment's camaraderie: they both thought that it would be nice if they lived long enough for any of the things Pycelle was talking about to have even the slightest chance of happening.

"Small children often put things in their mouths that they shouldn't. They can't help it: they don't know any better. When you are mothers, or if you're ever put into a situation where you have to look after someone else's children, it will be up to you to prevent them from trying to eat anything dangerous. For example, there are a number of poisonous berries that small children seem to find attractive," said Pycelle, picking up one of the books from his desk. "Holly has shiny red berries that are highly poisonous. Because their taste is so acrid and unpleasant, under normal circumstances it is unlikely that anyone would eat enough of them that they would suffer any serious harm from it, but small children can be stubborn about such things. The bright orange berries of the spindle tree are similarly poisonous and unpleasant to taste."

Opening the book, which turned out to be a weighty tome of botanical knowledge, he showed them pages of detailed information about the plants he was referring to, including beautifully drawn and painted illustrations.

"Arum has many names: adder's root, adder's tongue, cuckoo-pint, snakeshead, dead man's fingers, lords and ladies, and wakerobin, among others. It causes itchy rashes to anyone who touches it. The berries are red or orange, extremely poisonous, and are most likely to be eaten by children attracted by their glossy appearance. Different sources say that their taste is either 'acrid' or 'insipid' and they contain a juice that causes burning pain and swelling when it touches any part of the mouth or throat. The consequences of swallowing them may include difficulty breathing, stomach upsets, and renal injuries," said Pycelle in the droning voice that usually caused Katarina to fall asleep in his lessons. "If you ate enough of them, it would take between ten and twelve hours for you to die in horrible agony."

"Because of their nasty taste, it's unlikely that we would eat enough of them to kill us, even if we were foolish enough to eat strange berries that we'd found in the woods," said Katarina. "But would it be possible for a poisoner to use them?"

"I suppose they could tie you down and force-feed them to you," said Pycelle. His derisive tone made it clear that he thought that this wasn't at all likely to happen.

Silently, Katarina vowed that she would protect Sienna from anyone bullying her and trying to force her to do anything she didn't want to do.

"It's much more likely that small children will try to eat them. That is what you must be careful of," said Pycelle. "When you have children of your own–"

"I'm nine years old!" Katarina snapped at him. "I'm not going to have children of my own any time soon, if ever!"

The maester seemed taken aback by her vehemence. He put on an ingratiating smile and said, "You'll understand when you're older."

"Can we get on with the lesson, please?" said Katarina, reaching for the book in his arms and turning to another page. She couldn't be sure of the scale, but there was an illustration depicting a plant with serrated leaves, thick stems covered in bristles, and clusters of white flowers growing on top. "What's that? I think I've seen it before. Is it poisonous?"

"No, not really," said Pycelle. Then, after considering for a moment, he amended that to, "Not in the traditional sense, at least. That's a giant hogweed. Skin contact with its sap can cause severe burns. Painful and potentially disfiguring, but unlikely to kill you."

In the privacy of her own mind, Katarina was already contemplating a scenario in which Sienna would be pushed into a giant hogweed plant and suffer agonizing burns, after which she would ask for milk of the poppy to numb the pain. Then, someone would accidentally or purposely give her an overdose, causing her death.

It won't happen, she told herself. I won't let it happen.

"Oleander is another plant that can be dangerous to touch. Its flowers and foliage can cause death if eaten. During the Civil War, some of the Mad King's men were foraging for food in the Whispering Wood. They cut oleander branches and used them as skewers to cook their meat. Almost all of them died of the poison," said Pycelle. "Also, it can be deadly to dogs and horses; so, if you ever go on a hunting trip in a place where it grows, you would be wise to keep your animals away from it."

Turning to another page in his book, he continued, "Fifteen of the scarlet berries of the white bryony plant are enough to kill a child, but they would have to be trying very hard to eat that many. The roots are particularly toxic. Entire families have died after mistaking them for parsnips and eating them – although it's somewhat surprising that they didn't notice the nauseatingly bitter taste."

"I suppose they must have been desperately hungry," said Sienna.

"Perhaps," said the maester, indulging her with a nod.

He went on to describe various other poisonous plants that could be mistaken for edibles: daffodil and snowdrop bulbs were occasionally confused with onions or shallots; hemlock water dropwort looked very much like celery, pignut, or water parsnips; and darnels bore a strong resemblance to wheat until the later stages of their growth.

"And there are a great many deadly poisonous mushrooms that can be difficult to tell apart from the edible varieties," said Pycelle. With unseemly relish in his voice, he went on to describe how someone would die in excruciating agony over several days if they ate a 'death cap' mushroom. "They are easily mistaken for edible puffball mushrooms and it has been reported that they taste quite pleasant."

Katarina promised herself that she would never eat mushrooms again, no matter where they supposedly came from or who vouched for them. And she would make sure that Sienna did the same.

"Of course, we owe a tremendous debt to the people of the ancient world, from before recorded history, who must have died in their thousands from eating poisonous plants and fungi," said Pycelle. "It is only because they bravely sacrificed their lives that we – the people of today – know what is good to eat and what is dangerous or deadly."

"A septa once told me that the Seven taught the first humans what they should eat, how to grow crops, raise cattle, and so on," Sienna piped up.

"You may choose to believe that. I couldn't possibly comment," said Pycelle, although his derisive tone of voice made it clear how he really felt.

He went on to describe deadly nightshade, a plant that produced poisonous berries that were perhaps more dangerous than any of the others he had listed so far because they had a sweet and pleasant taste. "They are exceptionally lethal," he said, with the air of a connoisseur. "Just two or three of them would be enough to kill a small child."

"So, not something that should be mixed into a fruit salad," said Katarina, trying to make a joke of it, although her voice was shaking.

"Not if you value your life, no," said Pycelle. He paused for a moment, running a hand through his long, snowy white beard. "I should warn you that if you use any of the knowledge that I have taught you today to harm anyone, you will likely be executed in a very painful and horrible way. The worst forms of execution are reserved for poisoners, as a warning to others who might be tempted to do the same."

"I don't want to hurt anyone!" Katarina protested. "I just want to know enough to keep myself and Sienna alive!"

However, a treacherous voice at the back of her mind told her that if Jeord died – if she poisoned him before he had a chance to kill her – she would be safe from the prophecy. It was a tempting thought, but she suspected that the consequences of carrying it out would be much worse than if she meekly accepted that she was going to die at Jeord's hand. If she killed him and anyone ever found out about it, she would be executed as a traitor to the crown and her entire family would be attainted. She loved her parents and didn't want them to be punished for something she had done, so…

I won't do it. She shook her head. I'll find another way.

Pycelle stared at her, a calculating expression on his face. "As you say, Lady Katarina," he said in a soothing voice. "I hope that I can teach you everything that you need to know."

Reading from his book of botanical lore, he began to speak at length about some of the myths and legends associated with the deadly nightshade plant: apparently, it had a spirit that could take the form of an exceedingly beautiful woman, but anyone who looked upon her would be fatally cursed.

"Also, it is one of four poisonous plants that are commonly believed to be used in witchcraft," said Pycelle. "When you visited Maggy the Frog yesterday, if she had tried to sell you a love potion, deadly nightshade would probably have been one of the main ingredients."

According to his book, other plants that folklore insisted were used by witches to brew magic potions included datura, henbane, and mandrake. All three of them caused hallucinations and in ancient times had been believed to have medicinal properties, although an overdose of any of them was likely to be deadly.

"Many centuries ago, mandrake was used as an anaesthetic. Physicians were able to perform complicated surgical procedures while their patients were rendered insensate by the mystical root. Kill or cure, I suppose," said Pycelle with a lofty eye-roll. "At one time, mandrake roots were considered to be more valuable than gold."

"Are they rare?" Katarina asked.

"Difficult to grow, certainly," said the maester. "They don't respond well to attempts to farm them."

He then described brugmansia, a plant that was difficult to tell apart from datura and had many similar properties. Apparently, ingesting it in sufficient properties induced a feeling of great relaxation followed by hallucinations and death. It was known to be a favourite of professional assassins who liked their victims to die quietly and without fuss.

Long ago and half the world away, poison hemlock had been used as a tool of execution by one of the vassal states that paid tribute to the Valyrian Freehold. It was a violent emetic that caused convulsions and death by respiratory failure. "Death starts in the feet and slowly creeps up the body," intoned Pycelle, quoting from his book. "The process can last up to twelve hours."

Black hellebore was another poison that had once been popular: centuries ago, it was used to poison arrows and daggers. "Some say that the crannogmen of the swamps near the Neck use it for that purpose, as part of a lethal mixture that they smear on their weapons. However, others have alleged that they smear their weapons with feces, snake venom, and the noxious secretions of various swamp-dwelling animals."

Pycelle continued in this vein for a while longer. He described the spring meadow saffron plant from the mountains of the Westerlands, every part of which was poisonous. Then he talked about box plants, which were often used for hedges despite the fact that their leaves and bark were poisonous. "The leaves can be dried and powdered to make the poison more concentrated," he said.

Finally, he talked about how every part of the foxglove plant was poisonous and that the seeds were deadliest of all, but that some maesters claimed to have used them to make medication that could give strength to a diseased and failing heart.

"Honestly, I could go on forever," he said at last. "Even if I took the time to tell you everything I know, it is possible that new poisons will be discovered or created before long. Besides, what are the chances that you will remember every last detail? Slim to none, I'd say. Instead, I think that it would be best if we focused on what sensible precautions you could take to keep yourselves from being poisoned, no matter what the poison happens to be."

Returning to his desk, he exchanged his book on botany for the other dusty tome he had brought with him. Katarina was somewhat disappointed when it turned out to be a history book. "One of the emperors of Old Ghis feared poison so much that he concocted what he claimed was a 'universal antidote', consisting of tiny doses of several different poisons that had previously been used to kill some of his friends and family, which he drank every day. In this way, over a number of years, he developed an immunity to those poisons. However, when he was deposed by one of his rivals, he tried to kill himself by drinking poison, but found that it had no effect on him. He was forced to beg one of his guards to stab him to death, rather than allow himself to be captured and publicly mutilated."

"So… what are you suggesting?" Katarina frowned. "From what you've said so far, it seems like there must be hundreds of different poisons! And some of them are very rare and expensive. I don't think it would be possible to make Sienna immune to all of them."

"You are right," Pycelle agreed. "And anyway, even if it were possible, I wouldn't advise it, for a number of reasons: first, it can be extremely difficult to tell the difference between a mild dose and a lethal one; second, there are poisonous metals such as mercury, which build up in the body over time and will kill you gradually, to which you can never become immune; and third, there are some poisons to which the human body tends to become sensitized rather than resistant. Strychnine, for example. If taken every day, the same amount will have a larger effect after several months than it did at the beginning; therefore, by attempting to build up an immunity to it, you would only end up killing yourself."

With a frustrated sigh, Katarina said, "That doesn't sound helpful. Why did you mention it if you knew that it wasn't going to be of any use?"

"You are afraid of being poisoned. Throughout history, there have been many important men and women who shared the same fear. By studying the methods that they used to protect themselves – as well as the mistakes they made – it is my hope that we can learn from them," said the elderly maester, continuing to leaf through his history book. "I suppose that you could employ a food taster. That would be traditional. The most common poisons tend to have a strong flavour that a food taster would be likely to notice and thereafter prevent his master or mistress from ingesting. However, some poisons are virtually tasteless, odourless, and take a number of days to kill someone. No one would be willing to wait several days to see if their food taster fell ill before starting each meal."

Still, it may be worth a try, thought Katarina. I will be Sienna's food taster. If she is poisoned, I will be as well. If she dies, I will die too. By doing that, she reasoned, she would prove that at least one of Maggy's prophecies was false.

"After King Daeron I Targaryen was shot with an envenomed arrow, he was healed by his cousin, Prince Aemon, who was a light mage," Pycelle read aloud. Flipping a few pages ahead, he summarized the events that had followed: "Daeron made a full recovery, although he was later betrayed and hacked to pieces by several dozen Dornishmen. Aemon would go on to heal King Baelor I after he'd been bitten by a dozen venomous snakes, but could do nothing to save him from fasting himself to death. After that, he saved King Viserys II from a poisoning attempt, restoring him to perfect health even after the king's doctors had said that he would surely die." Looking up from his reading, he gazed triumphantly at Katarina. "Well, there you have it! If you want to be kept safe from all manner of deadly poisons, I suggest that you befriend a light mage and stay close to him at all times."

"But… where am I supposed to find a light mage?" asked Katarina. "They're very rare, aren't they?"

"Only five of them are known to have been born in the last hundred years," said Pycelle, sounding sickeningly cheerful.

"An impossible task," said Sienna, lowering her head as if stricken with weariness.

"Not impossible," said Katarina. "Just incredibly difficult."

"I think that it is nearly time for lunch," said Pycelle, looking at the clock. "We'll end it here for today. I expect to see you here again tomorrow: you have lots of arithmetic to catch up on!"

At that, Katarina sighed and slumped in her seat. Next to her, Sienna smiled warmly and put a reassuring hand on her shoulder.

Later that day, after a lunch during which she had received several odd looks because she insisted on eating a little of everything before Sienna did, Katarina stepped out into the garden, hoping that she would have some time for play before she was called inside for her music lesson. She yawned, stretched out her arms, and glanced at her best friend to make sure that she was safe and well, which had already become something of a reflexive habit.

Then, she saw it, growing out of the lawn: a tall, impressive-looking plant with serrated leaves and an umbrella-shaped cluster of white flowers growing out of a thick, bristly green-and-purple stem. Of course, she recognized it immediately: it was a giant hogweed.

"Stay behind me, Sienna!" she cried out in panic.

"It's a plant. It can't move," her best friend pointed out.

"Then how did it get there?" she asked. "It wasn't there yesterday."

Sienna had no answer to that. "I suppose we'd better tell someone."

"You need to stay where it's safe," Katarina told her. "Where's Anne? She'll look after you."

"She has other duties. I don't want to be a bother…"

"Nonsense! Keeping you alive is more important than anything! Now, come on!"

Leading Sienna by the hand, Katarina raced inside, looking for someone who could help her to deal with the problem of the poisonous plant that had appeared out of nowhere.

She found two of the former bandits she had recruited to guard her when she was heading from her fateful meeting with Maggy the Frog: a man with rotten teeth, whose name was apparently 'Lem Lemoncoat', although he had been forced to leave his namesake coat in his living quarters while he was on duty; and a grey-haired man who appeared to have moss growing in his beard, whose name was 'Pello'. They were serving as household guards, at least temporarily, until her father found a better place for them.

"There's…" She gasped for breath, coming to a sudden stop. "…a giant hogweed on the lawn!"

"The filthy beast!" cried Lem Lemoncoat, reaching for his sword.

"Did it hurt you?" asked Pello, looking anxiously at the two girls. "No, it doesn't look like it, but… I suppose it must have come as a dreadful shock, seeing a huge pig pissing on the grass like that."

"It's a plant," Sienna informed them.

"What?" asked Lem. "I mean, I beg your pardon?"

"A giant hogweed is a type of plant," said Katarina, when she'd got her breath back.

"Oh." Lem looked vaguely disappointed. "Not any kind of urinating swine?"

Sienna shook her head. "No."

Lem took his hand off his sword hilt. "In that case, you need a gardener, not a guardsman."

"Not the same thing, even if the words sound similar," said Pello. "Easy mistake to make, I suppose."

"It wasn't there yesterday!" Katarina exclaimed.

"That's strange," said Pello with a nod. "You should talk to a gardener about it."

A couple of hours later, after Katarina had explained the situation to one of the gardeners, the giant hogweed had been dug up by the roots, chopped to pieces, and burnt. Meanwhile, she'd had to go to her music lesson, during which she was unable to concentrate because she was wondering how else Sienna would manage to nearly get herself killed.

"What is the matter with you today?" her music teacher scolded her. "Where have you left your head? It certainly isn't here with us!"

She and Sienna shared a meaningful glance, knowing that it would take too long to explain and that they probably wouldn't be believed.

Fortunately, they both managed to survive until dinner that evening. They were given a little time to play out in the garden beforehand, which was cut short by the fact that, before they could start, they needed to check that there were no more dangerous plants or fungi in the area where they would be playing. They tried to make a fun game of it, but they knew that it was deadly serious.

"I suppose we'll have to do this every day from now on," Sienna said dismally.

Katarina nodded. She could see no alternative.

Author's Notes:
My interest in poisons was first piqued when I visited Alnwick Castle, in Northumberland, which has a 'Poison Garden' that visitors can pay to be shown around. It contains a wide variety of poisonous plants, including cannabis, coca, and opium poppies, and the guides are knowledgeable and informative. An expensive day out, but I think that it was worth it. (And yes, in case you were wondering: they also have a gift shop.)

Anyway, this chapter was the result of quite a lot of research into different types of poison. I suspect that I've been put on a watchlist somewhere. I hope that it was worth it.

Considering how many works of fiction seem to take it for granted that their characters can become resistant or immune to poison by taking small doses over a long period of time, I was interested to find out that the reverse can also happen: certain drugs and poisons cause the body to become sensitized, meaning that tiny doses taken over a long time will start to have more of an effect than if that person had never taken that particular drug or poison before. Strychnine is the example I have given above, but there are others.

Jeord will be the star of the next chapter. Look forward to that!