This night, both of them slept for a very long time.

The fatigue caused by long-term mental tension is very strong, although their strength is very strong now, and their physical fitness has been greatly improved, they still need to rest to recover better.

However, there is no sense of time here, and it feels like a night of sleep when you wake up naturally.

Wu Hao still got up earlier than Ling Fei'er, and didn't bother her, got up and grilled a piece of fish and made a pot of fish soup.

"Get up, girl. ”

When he was ready, he picked up the little girl from the ground.

"Brother Linghao is early. ”

Ling Fei'er stretched lazily in his arms, hugged him tightly and didn't want to get up, every time she woke up, this little girl was an out-and-out eldest lady.

"Drink some water and get up to eat. Wu Hao put her on the ground.

"Oh. ”

Ling Fei'er yawned heavily, but the stone cup in his hand was rinsed, and the rest of the water was gulpled and drunk.

"What are we going to do today?" Ling Fei'er asked as she ate, just woke up from her sleep, obviously out of shape.

"Continue to explore and try to find the third cave as soon as possible. The next thing we have to do is keep moving forward. Wu Hao said.

"Okay, we'll get to work after eating and resting. Ling Fei'er grinned, without the slightest hint of distress, Wu Hao smiled and touched her head.

After eating and resting for a while, the two men undressed and jumped into the water.

Now there is no need for a person to carry the spars, two people can start work together, the efficiency is directly doubled, insert a spar every five meters, insert a spar every five meters, all the way forward, a day down is to advance more than 13,000 meters, with their current physical fitness, stay in the water for a few more days, it is not a problem at all, so before they are hungry, they have no intention of resting, all the way forward to insert the spar on the stone wall, when they reached more than 17,000 meters, a blue light in the distance attracted their attention, the two people glanced at each other, and immediately swam towards the blue light。

It's a new cave again.

Directly below the blue light, the two people were excited.

This cave is very small, the opening is only less than ten square meters, and it is estimated that it is also a very small karst cave inside, but it doesn't matter to them, what they need is not necessarily a big karst cave, as long as it is a karst cave, it is enough to accommodate them to rest and breathe.

The two men jumped up and flew into the cave.

As Wu Hao expected, this cave is very small, estimated to be only about 100 square meters, and the height is also very low, flying too high, and if you are not careful, you will touch the top of the stone wall.

But it doesn't matter, as long as he's a cave and can accommodate them for a little rest, that's enough.

"Let's go, let's go back. ”

The corners of Wu Hao's mouth lined up, and he pulled Ling Fei'er to jump into the water again, and returned to the second cave in the direction guided by the spar.

Since there is already a new cave, then the power of this cave must not be wasted, the two of them began to absorb the power of this huge cave, the blue light of the cave gradually turned dark blue, and the dark blue gradually became darker until it disappeared.

Returning to the water, swimming all the way to take back the spar on the stone wall, the two people came to the newly discovered cave, threw the fish in the space ring back into the cave for refrigeration, the two of them cooked a pot of fish soup, warmed their bodies, and did not rest much, they jumped directly into the water and continued to look for a new cave.

The strength in their bodies is becoming more and more abundant, and their physical functions are becoming more and more powerful, whether it is the ability to resist hunger or cold, or the duration of power output has greatly increased, the most direct manifestation of which is that their work efficiency in the water is getting higher and higher.

After entering the water once, I advanced more than 30,000 meters directly in the water, and finally found the fourth cave.

But this cave was completely different from the first three caves they found, and what they saw from a distance was not a blue light, but a red light.

The red light was far away from them, but the light was very strong, and the water temperature increased significantly as far as the line of sight could see.

Could it be a cave made of hot stones?

With questions, Wu Hao pulled Ling Fei'er and quickly came to the bottom of the cave.

Hot!

Even if they haven't gone up yet, Wu Hao can be sure that this karst cave is definitely a huge karst cave composed of hot stones, which has not yet gone up, feeling that the water below the karst cave is about to boil, fortunately, their physical fitness is strong enough, otherwise they will not be able to stay in such a water temperature at all.

This hole is about the size of a football field, how much space will there be in it?

Wu Hao calmed down his emotions and pulled Ling Fei'er into the cave.

Huge heat!

It was as if entering a huge oven, and the moment they entered, the water vapor on the two people was evaporated and dried, and hot smoke was emitting from their bodies.

The water pool in the middle of the cave kept emitting white smoke, but the cave was too hot for water vapor to gather, and the cave was wet and stuffy.

"This cave is so big. Ling Fei'er looked around at the cave in front of her and was surprised.

"It's big enough. "This cave is 100,000 square meters, right?

"But it's too hot to stay in. ”

"But the energy here must not be wasted, if all the energy here is absorbed, hehe. Wu Hao smiled without saying a word, and flew directly to the top of the cave to begin to absorb the energy of the hot stones in the cave.

"Hee-hee. Ling Fei'er was not polite, she grinned and casually found a place to start absorbing.

Although the ice stone and the hot stone release two different temperatures, but the structure is similar, with the decrease of energy, the release of heat will also decrease, which will lead to the decrease of temperature, Wu Hao and Ling Fei'er quickly absorbed the hot stone energy in the cave, the temperature of the cave gradually began to drop, the initial decline rate was very slow, but as their absorption rate became faster and faster, the more energy they absorbed, the faster the temperature dropped later, when the orange-red light in the cave gradually turned into a dark red light, the temperature in the cave was estimated to be only more than 20 degrees, reaching a temperature range that is most suitable for rest。

Wu Hao didn't know how long it took to absorb these powers, but he was very satisfied with the power accumulated in his body.

took Ling Fei'er back to the previous cave, grilled a piece of fish, cooked a pot of fish soup, rested a little after eating and drinking, put away the remaining fish, absorbed all the energy in the cave, and returned to the hot stone cave while collecting the spars.

The oxygen in this cave is insufficient, it is not suitable for a long stay, Wu Hao does not plan to stay here for a long time, he just wants to use it as a temporary foothold, and the two of them did not rest, and directly started to explore the next cave.