This scene made Chu Nan's curiosity even more.

After a closer look, he found that the cyan at the bottom of this suspected ancient castle was covered with esoteric and complex runes, and just looking at it made him feel dizzy.

And this cyan occupies all the space above, so even if he wants to continue to spread upwards, there is no room to continue to spread.

Chu Nan felt that it was necessary for him to figure out what the cyan above was, so he spread along this cyan to the left.

This cyan is too huge, and Chu Nan's roots have spread far away, and they are still covered by this cyan.

Meanwhile.

Chu Nan also found a lot of chains under this cyan color one after another.

Every once in a while, a huge chain would fall from the cyan.

And Chu Nan tried to touch this piece of cyan after trying to touch it.

I couldn't help but suspect that this piece of cyan was probably not the bottom of the castle.

After all, he had felt very clearly about the castle, and the entire castle exuded a terrifying heat.

Earlier, when he was in the second stage, he didn't dare to approach easily under the heat emitted by the ancient castle.

And this cyan was now cold to his touch, without any sense of heat.

This also made him have more doubts in his heart.

Accelerates the spread of tree roots.

After reaching the third stage, in terms of the length of the tree roots, Chu Nan could already reach a rather terrifying length.

However, even this length did not reach the end of this cyan.

This shocked Chu Nan's heart, and at the same time, he had to move the tree body and move forward.

After he broke through to the third stage, the high temperature that his body could withstand was also greatly improved, and he could get closer to the ancient castle more.

That's it.

After he had traveled some distance from the tree, the length of the roots had finally reached the end of this cyan!

He found ......

At the end of the day, the flames were gone!

It seems that these flames only exist in the area where cyan is located.

Once you leave the area, the sea of fire will disappear with you.

"I'd like to see what this is!"

Chu Nan took a deep breath.

The roots of the tree began to extend upwards, and the whole person was watching intently.

"This, this is ......"

Gradually, he saw clearly what it was that existed above the sea of fire!

The pupils of the whole person instantly rounded, his face was full of shock, and his mind was full of thunder.

He didn't think of it anyway......

This one that existed above the sea of fire would be a cyan ...... Stove!

The whole stove is just too big.

The cyan that Chu Nan saw earlier was the bottom of this furnace!!

And this stove obviously still exists under the castle.

"That is to say, this furnace exists under this castle! And under this furnace, there is a great sea of fire, and those hot breaths come from this sea of fire!"

Chu Nan finally understood what was going on at the bottom of this ancient castle at this moment.

And the existence of these seas of fire seems to be cooking something for this stove......

This couldn't help but make Chu Nan's curiosity even stronger.

At first he was attracted by the heat, but after coming here, he found out......

The sea of fire that emits these hot gases is just providing heat to this huge furnace, and the contents of the furnace are the greatest value here!

Chu Nan's heart couldn't help but thump.

I'd love to see what's inside this stove.

The roots of the tree continue to spread upwards.

Because this furnace was so big, after spreading for a long time, Chu Nan finally reached the top of the furnace.

Here we are......

He could finally see what's going on inside the stove.

Although in the process of spreading, he already had a lot of reverie about the contents of this furnace, but when he saw it with his own eyes, he was still shocked by the contents of this furnace!

In the midst of this huge furnace......

There is a huge giant!!

This furnace was already extremely large, but it could not contain the entire huge giant, and you could see that the giant's feet had already stretched out of the furnace.

The giant had black skin, covered with swirling secret lines, and wore a large white mask that obscured his face, and was dressed in a black robe.

His body had long since lost any life, and he was already a cold corpse.

But even the corpse still had a terrifying aura, emanating from him, causing the surrounding void to tremble and distort.

Among them, Chu Nan felt the most shocked was a single horn on his forehead......

Although Chu Nan couldn't see his face because of the mask he was wearing, the moment he saw this single horn, a sense of familiarity suddenly came to his face, filling Chu Nan's entire mind, making him instantly realize that the giant corpse lying here was a ...... Demon!!

"Here...... There's a demon!"

Chu Nan was a little distracted.

Whether it was the size of this demon or the demonic qi escaping from the horn on its forehead, Chu Nan understood that this demon's identity and strength must be extremely high before his death.

But now it's long gone......

It is placed on this huge stove and baked.

Chu Nan even saw that one of his fingers seemed to have been melted by the furnace and turned into a black liquid, flowing in the furnace.

"This world of trials...... What the hell is it!"

When Chu Nan first entered this world and became a tree spirit, he felt that this trial world might be a high-end fantasy world.

After all, it turns people into dryads......

In his mind, it was only possible to do it in the fantasy world.

But the moment he saw this demon, he denied the possibility that this was an illusion world!

It was the feeling that this demon had brought him, and it was extremely real, so that he could be sure that this was definitely not an illusion world.

This world ......

Far more unfathomable than he could have imagined!

Chu Nan took a deep breath.

He knew that with his current cultivation, it was obviously unrealistic to explore the secrets of this world.

However, the black liquid on the stove made him feel excited.

Although he didn't know why this stove was baking this demon, after this demon's fingers melted into a black liquid, Chu Nan felt that maybe he could try to absorb this black liquid!

Of course, there may be some risks involved.

However, after a short period of measurement, Chu Nan still gritted his teeth and decided to take a gamble!