In the northwest sea of the North Demon Plain, near the edge of the no-man's land, there is a headland, there is a long coastline, a 100-meter-high cliff, and what makes people even more shocking is that between the cliff and the sea, there are tens of thousands of huge stone pillars of different shapes distributed in an orderly manner.

These stone pillars are uneven, staggered, more than ten meters high, five or six meters short, after the perennial invasion of the sea breeze, the surface of the pits and pits are dotted, showing the vicissitudes of the years, extending from the cliff to the sea, forming a giant staircase that winds thousands of meters, looking at it from afar, it is natural, magnificent!

At the top of the cliff, there is a flat plateau covered in gently undulating low green grass and moss, and in the summer, the highlands are covered with small purple flowers called cow orchids.

The boundless purple, the lingering floral fragrance, not strong, but intoxicating!

In the middle stands a huge iron-gray castle!

The castle is a typical Beiyan architectural style, simple and heavy, the lines are tough, the whole is built with basalt, about 50 meters high, covers an area of 20 hectares, faces the sea in the north, the other three sides are markets, squares and residential areas, the main body of the castle is mainly composed of residential areas, stables, garrison areas and central districts, a total of five layers, the city wall of three kilometers long surrounds the castle.

The Northern Demon Yuan was not allowed to build a city, but this castle is like a small city!

In the Northern Demon Plains, this road, this cliff, and this castle are all famous!

The road is the Giant's Causeway!

The cliff is the end of the sky!

The castle is called Ironclad Castle!

Many people may have walked this road and climbed this cliff, but no one dared to enter this castle.

Because this is the head of the four major families of the Northern Demon Plain, the Ji family's Iron Castle!

Compared with the noisy and prosperous Jinguang Town, there are no other buildings within a radius of several miles near the Iron Cloak Fort. Except for the sound of the sea breeze and the call of seabirds, it is difficult to hear any other noise, and the silence is somewhat terrifying.

Facing the boundless sea, with flowers on its side, the Iron Castle with a closed gate all year round looks stubborn and arrogant!

At this time, in a dark room in the fort, two voices, a man and a woman, were talking.

"You've decided?" The voice is clear, the tone is subdued, and he is a young man.

"Well, the Jin family is ready to move, and after preparing for so many years, they won't stop easily." It was a woman, her voice was a little low, and she couldn't tell her age.

"Isn't that a bit risky?" The young man asked with some caution.

"What day are we not adventuring?" The woman asked rhetorically.

"That's right!" After being silent for a while, the young man suddenly said, his voice becoming a little gloomy: "Uncle Jun died yesterday!" ”

"How did you die?" The woman was a little surprised, her voice still low.

"He met a white-haired dire lion!" The young man's voice was a little helpless.

"The little brother must be very sad to know, you have to avenge him!" The woman was silent for a moment before speaking.

"Revenge has already been avenged, who am I?" The young man had a hint of smugness.

"That's good!" The woman was a little absent-minded.

"Hey, my little brother has been drifting outside for so many years, it's time to go home! If you have the opportunity, persuade him, don't always be obsessed, the old man still lives in a no-man's land at this age, and he doesn't have a few years to live. The young man said earnestly.

"I'll give it a try!" The woman's reply was perfunctory.

"I heard that he also practiced Gang Qi last year?" The young man asked.

"Well, he has a very high talent for martial arts!" Speaking of her little brother, the woman did not hesitate to praise it.

…………

"When are you going to do it?" The young man asked familiarly.

"It should be soon!" The woman thought for a moment and said.

"Okay, if you need help, you can send someone to talk to me, and I was thinking about meeting that Huang Puyu?" The young man was a little eager to try it.

"Well, thank you!"

"Hey, why are you so outside? I'm your brother! ”

"Okay, then no thanks!" There was a hint of playfulness in the woman's words, and with that deep voice, there was a different kind of temptation.

"By the way, the person that the younger brother said, have you checked it carefully?" the young man suddenly thought of something.

"Well, I'm sure it's someone from the Sang family!" The woman spoke slowly and logically, but her tone was unquestionable.

"The Sang family? It's been so many years, why did anyone suddenly think of touching them? The young man seemed to be talking to himself.

"I don't know, but I'll investigate it myself!" The woman's words are categorical.

"How are the San people doing now?" The young man asked suddenly.

"The thousand-year-old foundation will be destroyed in one fell swoop!" The woman sighed, and seemed to feel some regret.

"The old nest has been copied, what can you do here?" The young man was somewhat dismissive.

"The Sang clan has fulfilled its promise for so many years, it's not easy!" The woman was a little silent, and her words were uneven: "And I heard from the little brother, that kid is weird and has a lot of eyes, and it seems to be quite interesting, I'll go see him later!" ”

"Kid?" Young man strange.

"Well, it looks like I'm only fourteen!" The woman said in a calm tone.

"You're going to work with a kid?" The young man asked, puzzled.

"What's the problem?" The woman is as if nothing happened.

"You!"

…………

Spindle Valley, inside room two, looks a little cluttered at the moment.

On the workbench, there are various tools such as medicine jars, medicine mills, copper scales, and stoves.

On the shelves, in the corners of the room, there are all kinds of materials, including plants, liquids, ores, bones......

"Half a penny for red letterstone, one penny for yellow alum, three coins for green skin......"

Mei Dongen, who was tightly wrapped all over his body, whispered while weighing the medicinal materials in his hands with all his attention, Sang Nan also stood aside with gloves and masks, staring at Mei Dongen's hands with his eyes, these materials contain different degrees of toxicity, once the operation is wrong, the consequences are very serious.

Sang Nan was a little nervous because they were trying a new way to refine the poison.

This method is provided by Runye.

In the past two days since he was recuperating, Sang Nan always ran to him with something to do, asking him some questions about alchemy. Runye understood Sanan's thoughts, and he didn't hide his secrets, and told him the knowledge system of alchemy, as well as some commonly used recipes.

These contents are not complicated, but for beginners, it is still a little obscure, but fortunately, Sang Nan knows some methods of dispensing medicine, and soon memorized the content introduced by Runye silently in his heart, and quickly digested and understood.

However, Runye didn't have any experience in refining toxins, and he didn't understand the toxicity and principles of various poisons, so after thinking about it, Sang Nan still found Mei Dongen and expressed his thoughts euphemistically.

Who knew that Mei Dongen did not hesitate at all, and immediately nodded in agreement, and the happy look was as if the poison he had made was a delicious sugar pill, without the slightest pity and sadness.

Seeing the black line on Sang Nan's head, he was puzzled in his heart.

Didn't she know that these poisons were used to kill?

Red letter stone is not very toxic in its natural state, and at most it can make people dizzy and have a fast heartbeat, because it is also mixed with many other ingredients. Based on Runye's alchemical theory, Sang Nan deduced that when the red letter stone is mixed with yellow alum, and then added to the green skin liquid, it can produce an extremely pure and highly toxic substance, which is enough to kill people. In this way, the school of poisoners at that time should have many similarities with the theory of alchemy.

The two of them carefully ground the red letter stone and yellow alum into powder, and then put it in a pottery Gu, then mashed the green leaves into juice, and then filtered out the dregs, and then poured the dark green juice into the pottery Gu, and then put it on the fire to heat it slowly......

After about a cup of tea, the three substances began to react. Slowly mixed together, and finally formed a somewhat viscous, milk-like substance at the bottom of the pottery Gu.

The two looked at each other with a hint of excitement in their eyes.

After the Tao Gu had completely cooled, the thick white milk began to harden slowly, and finally formed a layer of white crystals.

White crystals, crystal like jade, Sang Nan and Mei Dongen both thought of a question at the same time:

Who will you ask to test the drug?

There were quite a few critters near the valley, but the thought of watching them die later made Medon give up on the idea.

Seeing that she was back to normal at the moment, Sang Nan didn't say much, rubbed her forehead, and pondered who she should find to test the medicine.

After a long time, Sang Nan suddenly rolled his eyes, raised his head, and said to Mei Dongen with a stiff face:

"Ahem, that, why don't you let the silver mink try it?"

Mei Dongen suddenly felt that his heart was full of sword thatch, and the more it grew, the more it grew!