Hydrogen Grenade

After this incident, the two of them became even more diligent in their cultivation.

Though no one said it aloud, everyone understood that since all hope in this place had been cut off, cultivating quickly and increasing their strength was the most important thing right now.

No one knew whether tomorrow or an accident would come first.

Huo Yun'er saw it all and ached in her heart. There was little she could do; she could not cultivate in place of the two children, so she could only put effort into her cooking. Almost every day, she made different dishes. They were not particularly refined in appearance, but they were quite delicious.

Even in such a crude environment, Lin You could not stop praising her cooking. One could only imagine her skill in that regard. The reason Huo Gua could hook people with his grilled fish was probably because he had inherited it from his mother.

In truth, Lin You knew very well that taking Huo Yun'er away from this place sounded simple, but was actually extremely troublesome.

The White Tiger Duchess had never relaxed her vigilance or surveillance here. Though she had not used any forceful measures, the moment Huo Yun'er showed the slightest sign of wanting to leave, whether through the side gate or by climbing over the wall, she would definitely be stopped.

And even if she did leave, with the stamina of an ordinary person, she would not get far. Once she was caught, it would become a fight to the death.

The reason Huo Gua had been able to leave openly through the side gate was likely because Huo Yun'er would remain in the residence forever, so they could not be bothered to make things difficult for the boy.

From a certain perspective, harming Huo Yun'er was merely a matter of succession, but laying hands on little Huo would mean killing an heir. The two were fundamentally different. Even this lady from the Star Luo Imperial Palace did not dare act too boldly.

But now, they wanted to take Huo Yun'er away. That was entirely different. Thus, he had also been planning how to leave this place quickly, efficiently, and safely.

Walking? A carriage? They were far too slow and could easily be caught by soul masters—and caught by nothing more than flesh-and-blood legs at that.

Even Soul Grand Masters in their twenties had once traveled four hundred li a day during the training of Tang San and the others in the first era of Douluo. Compared to ordinary people, they were practically superhuman.

And there was no room to evade. Once the speed increased, the bumps and jolts in the wilderness would probably take half her life without anyone needing to make a move.

If the ground would not work, then...

As Lin You trained with Huo Yuhao in a relatively small area, he continued thinking it over. Before he realized it, he glanced at the bright sky, and an idea flashed through his mind.

If they could not travel by land, could they take to the sky?

If they flew high enough, ordinary Soul Skills would not be able to hit them. Moreover, most flying martial souls could not fly very high. Only after attaining a Martial Soul Avatar would they gain the ability to fly at high altitudes. In other words, if he made a hot-air balloon, a few thousand meters up in the air would be absolutely safe, leaving them free of all worry.

But after thinking it over, he felt it was still not safe enough. A hot-air balloon was too large a target; even a small breach would make it fall immediately. Not to mention that the sky was not safe either. If a couple of flying Soul Beasts appeared, they would basically be finished.

The accident rate at high altitudes was low, but once an accident occurred, the death rate was almost one hundred percent!

After considering it again and again, perhaps only a Flying Soul Guidance Device could provide high-altitude, high-speed, and safe travel. But soul guidance devices were things only soul masters could use. Although he understood how to produce hydrogen energy and had even attempted electrostatic-confinement Nuclear Fusion experiments at school, he knew absolutely nothing about soul guidance devices.

After training, Lin You sat atop a huge rock, basking in the sunlight with one hand supporting his chin as he thought quietly. Huo Yuhao, already drenched in fragrant sweat, had left to return to the house and wash up.

"We're too young and lack the materials. Otherwise, I could make a thermal engine or a steam engine too. Sigh, it seems we'll have to face them head-on after all. I need to prepare early."

With a soft sigh, he jumped down from the boulder. No matter what, without sufficient strength in this world of soul masters, he would at best be a clown leaping about, destined to be kicked to death like a dog on the roadside.

He had to get moving as soon as possible.

Amid the tense preparations, even time slipped through their fingers unnoticed.

Summer passed and winter came. In the blink of an eye, four years had gone by.

The small woodshed gradually became unable to accommodate all three of them. To avoid suspicion, Lin You had specially built a small house next door a few years ago and slept there. But as Huo Yuhao clamored about cultivating together, he had no choice but to clear out half the room and hang up a cloth partition. What had once been a luxurious suite instantly became one large single room, leaving him utterly depressed.

Over the past few years, the White Tiger Duchess had made no moves. Though Huo Yun'er remained uneasy, things were generally safe for now. She quietly breathed a sigh of relief, thinking that perhaps the other woman had been magnanimous enough to forget about her.

However, the guards and watchers nearby had not eased up in the slightest. In fact, their numbers gradually increased as time passed.

Inside the small house.

Lin You and Huo Yuhao were discussing something.

"Brother, when do you think we'll leave?" The little cutie before Lin You blinked her crystal-clear, gemlike eyes and asked eagerly.

She could no longer endure this life of being watched. It had been bearable before, but as she grew older, she felt increasingly in need of some private space. Those people were like flies—far too annoying.

"With this, we shouldn't have to fear those guys anymore, right?"

As she spoke, Huo Yuhao lifted the greenish-brown object hanging at her waist, which looked like a grenade. Her eyes were full of excitement.

You-ge had invented this thing himself. Its main component was a gourd, together with a pull ring, a firing pin, and a percussion cap. According to him, it was filled with high-purity hydrogen that he had specially prepared. Though it looked small, as long as the pull ring was removed, allowing the hydrogen inside to mix with the air outside, it could then be thrown out. The impact would trigger the firing pin, causing the percussion cap to ignite with only a small amount of external force. That would set off the hydrogen, creating an explosion and injuring the enemy.

Because the gourd was highly airtight and made entirely from tough woody fibers, it possessed a certain degree of strength and flexibility. Its inner space therefore formed a relatively stable microenvironment, one that helped maintain the temperature and humidity of the substances inside. In other words, once a Hydrogen Gourd Bomb was made, as long as no one tampered with it, it could last for a very long time.

Lin You roughly estimated that a Hydrogen Gourd Bomb could remain capable of dealing effective explosive damage for at least a year. As time passed, however, its internal hydrogen would gradually leak away. Even so, it would still retain explosive properties, because the concentration he had added was extremely high—not some paltry 4% concentration from an elementary school experiment.

"This thing should be more than enough to blow an ordinary soul master to death. I also added a few extra ingredients inside. Even if a Soul Elder had no defensive Soul Skills or soul guidance devices, getting hit head-on by it would cost them more than half their life."

He made a rough calculation of its power and gave an approximate figure. The specifics would have to wait until actual combat.

After all, it had been made by hand, so its quality was not that high. If he used uneven but seamless thin Iron plating as its shell, it could also create a fragmentation effect and deal even greater damage.

If Huo Yuhao had the Ice Jade Emperor Scorpion, that ultimate martial soul, then he could continue exploring the potential of hydrogen bombs—for example, Liquid Hydrogen, a super chemical weapon in which one kilogram of explosive force was equivalent to several hundred kilograms of TNT.

But producing Liquid Hydrogen required an environment of at least minus two hundred degrees Celsius before gaseous hydrogen could gradually turn into liquid hydrogen, so there was no need to consider it for now.

"It can even injure a Soul Elder? That's amazing!" Huo Yuhao's eyes immediately lit up when she heard this.

"Hmph, don't forget, these are only half a jin each for easy carrying. We can even tie them together to make a Cluster Bomb. As for the power... it would probably blast us into the air first, then blow up the entire house, right?"

Lin You smiled. Over the past few years, merely making a percussion cap had given him a splitting headache. Now that he had such results, it was only natural.

"Ah? That dangerous?" Hearing Lin You say this, the girl's expression changed drastically. The motion of tossing it about in her palm instantly stiffened.

"Don't worry. Simple impacts are fine. It only ignites after you pull off the ring and then strike it."

"Over the past two days, I've observed that there's an incense-stick gap in their shift changes. They probably think nothing has happened after guarding this place for so many years, so they've let their guard down and developed the habit of going to the toilet at fixed times. The people on the morning shift like to take care of their business one incense-stick before the night shift comes to relieve them, so we can quickly slip out through the side gate during that window."