Ascending from the mortal realm to become an immortal begins with taking charge of a grotto-heaven.

After leaving Yuntian Garden, Zhang Li strode towards the outside of Yunyu Immortal City.

Along the way, he passed some stalls set up by independent cultivators. Looking at the bustling crowds around him, some cultivators were haggling over a few or even a single spirit stone like ordinary people. He watched all of this with a calm heart.

If it weren't for possessing a hidden paradise, I would have been one of them.

Just as Zhang Li was about to leave Yunyu Immortal City, a strange noise suddenly broke out.

Sensing the unusual activity emanating from the [Cave Heaven], he was shocked, but he remained calm and continued forward.

Zhang Li pretended to be a rogue cultivator, glancing around at the surrounding stalls while constantly wondering what had caused the anomaly in the [Cave Heaven].

It should be noted that, apart from the first time entering the space and the time when it went into a state of demonic possession, the [Cave Heaven] has never shown the slightest movement on its own initiative, but this time it inexplicably produced some unusual activity.

After a moment, Zhang Li finally identified the source of the anomaly in the [Cave Heaven] and stopped in front of a small stall.

In front of me was a small stall with only a clump of dark, mud-like substance on it.

Although it looked somewhat unsightly, this mud-like substance did not emit any unpleasant odor; instead, it had a faint, pleasant fragrance.

"Spiritual Mud..."

Two words appeared in Zhang Li's mind.

He looked up at the stall owner behind him, a dark-skinned, thin cultivator in the mid-stage of Qi Refining. After glancing at the stall owner's attire, Zhang Li was certain of his idea.

Spirit Mud, the name doesn't sound special at all. It's just a kind of mud that contains spiritual energy. Only cultivators who don't understand its intricacies can interpret its meaning.

But the intricacies are far more complex than that.

This item is naturally formed and requires the fusion of underground spiritual veins, centuries of decay, and mountain spring energy over many years. Only through a series of fortuitous events can a small cluster of it be formed. It is quite difficult to replicate and refine by human hands, so it is not commonly seen.

The greatest use of spirit mud is to spread it in spirit fields, which greatly accelerates the rooting and maturation of spirit herbs and plants.

Judging by its effects alone, it is very similar to the Cave Heaven Black Field within his body, but the difference between the two is like the difference between a firefly and the sun. Even the best spiritual mud, in terms of accelerating the maturation of spiritual herbs and plants, is not even one ten-thousandth as effective as the Cave Heaven Black Field.

Even so, spirit mud is one of the few treasures in the cultivation world that can actively accelerate the cultivation of spirit plants, so cultivators who sell spirit mud to the outside world are generally independent cultivators.

If they were disciples of a sect, they would have handed it over to the sect long ago, and the sect's internal rewards would be more valuable than selling it directly.

At the very least, they should be sold to some cultivator families; selling them at a stall is a really bad choice.

However, the amount of spirit mud in front of us is not very large, so it's not surprising that it appeared here.

Seeing the gazes of the surrounding cultivators, the dark-skinned, thin stall owner revealed a satisfied expression. Rare items like spirit mud are not something everyone can find.

Zhang Li stood silently in the crowd, quite puzzled as to why the [Cave Heaven] would react strangely to a lump of spiritual mud that could accelerate the growth of spiritual plants.

There's really no logic to it.

Although he couldn't figure out why, he had already made a decision in his heart.

Everything concerning the [Cave Heaven] is of paramount importance.

After all, the [Cave Heaven] is the foundation of Zhang Li's cultivation, and he must obtain this piece of spiritual mud to find out the reason for the [Cave Heaven]'s anomaly.

Seeing that there were quite a few cultivators surrounding him, but none of them were taking the initiative to ask about the price, the dark-skinned, thin cultivator became a little impatient and took the initiative to speak up and solicit customers:

"Fellow Daoists, such a large piece of spirit mud is rare. Buying it will greatly accelerate your cultivation of spirit plants. You must not miss this opportunity."

Hearing the stall owner say that, Zhang Li couldn't help but chuckle softly.

Most of the cultivators gathered around the stall were independent cultivators, and even Zhang Li himself had changed his appearance and was not wearing the robes of a sect disciple.

Many rogue cultivators have no fixed abode and no suitable place to cultivate spiritual plants. Therefore, they will take away even if they encounter spiritual plants that are not yet fully mature, hoping to earn some money.

Therefore, there is absolutely no reason to sell or buy this piece of spiritual mud.

As the stall owner took the initiative to greet the crowd, the onlookers gradually dispersed, leaving only a few cultivators who were genuinely interested in buying the spirit mud, among whom Zhang Li was.

Seeing that the crowd of onlookers was dwindling and the stall was becoming increasingly deserted, the smugness on the dark-skinned, thin stall owner's face faded considerably, replaced by a hint of anxiety. He looked at the few remaining people, his tone becoming somewhat urgent: "Fellow Daoists, are you interested in this lump of spiritual mud?"

One of the cultivators who seemed interested in purchasing stepped forward. His strength was around the mid-stage of Qi Refining, and judging from his attire, he appeared to be a member of a family. He spoke with slight dissatisfaction:

"You're being unreasonable, stall owner! How are we supposed to bid if you don't put a price tag on the stall?"

The dark-skinned, thin stall owner wasn't annoyed by this. "Fellow Daoist, you seem to know your stuff. How about this, this lump of spirit mud will only cost one hundred and fifty spirit stones?"

Upon hearing this, the family cultivator's face immediately darkened. He didn't even bother to haggle and turned to leave.

The other cultivators who had originally intended to buy also turned and left upon seeing this, leaving Zhang Li alone in front of the stall in an instant.

"this……"

Zhang Li was speechless. He had originally planned to take advantage of the chaos and lower the price by having others bargain, but who would have thought that the stall owner's price would be so outrageous, directly deterring all competitors and leaving him the only one left at the stall.

Watching the cultivators leave, the dark-skinned, thin stall owner realized that his price had been too high, and his desire to make a fortune had suffered a crushing defeat.

Judging from its size and the spiritual energy it contains, this piece of spiritual mud on the stall is worth at most a hundred low-grade spirit stones. The price of one hundred and fifty spirit stones has far exceeded its true value.

Seeing Zhang Li still lingering in front of his stall, the dark-skinned, thin stall owner, as if seeing a last straw, asked hopefully:

"Fellow Daoist, would you like this piece of spirit mud? How about 130 spirit stones?"

Zhang Li didn't speak, but simply shook her head.

Seeing Zhang Li shake his head, the dark-skinned, thin stall owner became visibly anxious.

"Since you stayed until the end, you must be aware of the value of this spirit mud. One hundred and thirty spirit stones is really cheap. This is a treasure that can accelerate the growth of spirit plants. One piece can save you more than a year of cultivation time."

"Since you know I am a connoisseur, you should be well aware of the true value of this piece of spiritual clay. I advise you to make a proper offer, or you should simply keep this piece of spiritual clay for yourself."

The dark-skinned, thin stall owner's face alternated between pale and flushed as he stared at Zhang Li for a moment, weighing his options repeatedly in his mind.

There were no other potential buyers on the entire street. The spirit mud was useless to him, and he couldn't keep wasting his time guarding this lump of black mud. He gritted his teeth and conceded, "Then, fellow Daoist, name your price. As long as it's not too low, we can talk it over."

"Ninety low-grade spirit stones," Zhang Li said.

"Impossible." The dark-skinned, thin stall owner's tone suddenly became intense.

If he only had ninety low-grade spirit stones, he could easily find someone to sell them to; there would be no need for him to set up a stall here.

"Alright then, if you are truly interested in buying, take it for one hundred low-grade spirit stones. I won't sell it for even one less."

Seeing the stall owner's tone, Zhang Li knew this was his last line of defense, so he simply said, "Fine, one hundred low-grade spirit stones it is."

Without further ado, he took out spirit stones from his storage bag and handed them to the stall owner.

Looking at the spirit stones Zhang Li handed over, a clear look of greed appeared in the eyes of the dark-skinned, thin stall owner.

Zhang Li pretended not to see it, put away the spirit mud, got up and left, disappearing into the street corner in an instant.

The dark-skinned, thin stall owner looked up in the direction Zhang Li had left, packed up his stall, and quickly left.