The invisible sound barrier in the air is like an extremely elastic film blocking Zhang Tie's face.

This layer of film is not terrible, Zhang Tie feels that he is fully capable of easily passing through it and pulling it off, but I don't know why, Zhang Tie has tried many times, but he can't break through this layer of sound barrier.

The chakra of "Infernal Peng King Sutra" is still running calmly, providing Zhang Tie with an endless stream of strength, Zhang Tie feels that this speed is still not his limit, in terms of speed, the ability given to him by "Infernal Peng King Sutra" has not been utilized, but what makes Zhang Tie so depressed that he wants to vomit blood is that he obviously feels that he can easily break through this layer of sound barrier, but in fact, no matter how he tries and struggles, his speed is always hovering around 1200 kilometers per hour, This speed may already be intimidating for ordinary knights, but for Zhang Tie, it is not satisfied.

It's like driving a Drake T9, but you can only run slowly on the highway at 40 yards. The engine of the Croix T9 and the performance of this car in all aspects can fully support you to run more than 200 yards, and you are a racer yourself, but always, no matter how you step on the accelerator, you can only toss at 40 yards.

What's the problem?

If this happens in a sports car, it's probably because you didn't put the car's gearbox into a higher gear.

And for Zhang Tie, who cultivated the "Infernal Peng King Sutra", there was such a situation, obviously he had the powerful flying ability given by the "Infernal Peng King Sutra" but he couldn't burst out, and he felt that he could easily break through the sound barrier but finally stopped in front of the sound barrier, so. There is only one problem - in the complete "Infernal Peng King Sutra", there is definitely a corresponding flight secret method to match it. You can release the strong flying ability and talent of the "Infernal Peng King Sutra", and the "Infernal Peng King Sutra" mastered by yourself is incomplete. There is no corresponding secret method of flying, so I have this feeling of not being able to make it.

Above the stratosphere, Zhang Tie remembered that it should be the middle layer of the atmosphere.

Zhang Tie was trying to break through the sound barrier, and at the same time, he also felt the two obvious characteristics of the middle layer, the first characteristic of the middle layer is cold, the higher the middle layer, the colder it is, in the middle of the middle layer, the temperature can probably reach below minus 50 degrees, the so-called wind is biting. This should be the case, and the second characteristic of the middle layer is the very obvious convective movement of the air currents.

The temperature below the mesosphere is high and the temperature above is low, which is similar to the troposphere, so the mesosphere also has the convective movement of air currents in the troposphere, and it is more intense.

Zhang Tie didn't care much about the cold temperature. Whether it is his body protection battle qi or his own cold-resistant ability, it is superb, and the super strong airflow movement in the middle layer is for Zhang Tie. It's like an undercurrent at the bottom of the sea, which can be used as a flight aid for him, allowing him to use less force. can reach a large speed.

In the past, he felt the movement of the air flow by relying on the keen instincts cultivated by his body. And now, with the Eye of the Lotus Blossom. Because the movement of the air flow in the middle layer itself is generated by the temperature difference, Zhang Tie can even see the direction of movement of the air flow in the middle layer.

Under the eye of the lotus flower, the cyclonic air column generated by the invisible air flow in the middle layer is like a super large color-changing mushroom planted in the middle layer, these color-changing mushrooms, the small ones are tens of kilometers, and the large ones are thousands of kilometers, which is very spectacular.

Zhang Tie tried many times, relying on the effect of the airflow, it can indeed make him more effortless when flying, and sometimes more flexible, but no matter how strong the airflow, no matter how well he uses it, he still can't break through that sound barrier.

When ascending to the height of more than 400 kilometers at the top of the middle layer, Zhang Tie saw for the first time on the horizon in the distance, the outline of a faint arc of the earth under his feet, and at the same time of seeing this outline, Zhang Tie also felt a kind of pressure, which is very similar to the sound barrier, that is, you obviously feel that you have the ability to fly higher, but there seems to be a transparent ceiling on your head, preventing you from continuing to fly.

Zhang Tie knew that if he couldn't master the secret method of flight supporting the "Infernal Peng King Sutra", then the speed of about 1,200 kilometers per hour and the top area of the middle layer of the atmosphere more than 400 kilometers above the ground should be the ultimate speed and altitude of his flight that he can achieve now.

Zhang Tie had been flying in the middle layer for eight hours, and he had already flown out of the range of Zhongzhou and Longxi County.

After flying more than 9,000 kilometers, Zhang Tie didn't feel tired, he felt a little depressed, the thunder falcon in his perception flew towards him like lightning, with a speed of more than Mach 2, almost 3,000 kilometers per hour, and he was also not tired.

However, depressed to depressed, Zhang Tie also knew that this kind of thing could not be rushed, unless he could obtain the complete "Infernal Peng King Sutra", otherwise, if he wanted to improve his flying ability, he could only slowly find a way. But the complete version of the "Infernal Peng King Sutra", if there is really one, once this kind of emperor-level cheats appears, I don't know how much turbulence it will cause among the two races of people and demons, countless masters will compete, and a bunch of characters above the sky and the holy ladder will probably move, and he is an earth knight, in such a competition, it is estimated that he is not even qualified to play.

During these few hours of flight, Zhang Tie also encountered three waves of knights and two flying boats in the sky.

The two flying boats flew in the stratosphere, and Zhang Tie was not found at all, the two sides staggered, and the remaining two waves of knights, one wave was three people, two earth knights and a black iron knight, also flying in the stratosphere, this wave of people found Zhang Tie flying above them, but there was no communication, the two sides left, the second wave of knights were two earth knights, when they saw Zhang Tie, the two earth knights didn't know why, they seemed to be very curious about Zhang Tie's ability to fly in the middle layer, They chased Zhang Tie in the stratosphere for a while, as if they wanted to see Zhang Tie's appearance, but Zhang Tie had no interest in communicating with them, so he flew away directly.

Neither of these waves of knights flew faster than 900 kilometers per hour in the sky.

What really shocked Zhang Tie was the third wave of knights he encountered, the third wave of knights, in fact, there was only one person, and that was a phantom knight, a phantom knight flying in the middle layer with the magic entity of a hydra-headed snake...... (To be continued......)