If there was one thing Haku was absolutely convinced of, it was that nothing happened by chance. Everything in the world was the result of a complex chain of actions and reactions that ended up shaping natural phenomena. The smaller a phenomenon was, the simpler this chain was and the shorter the times; the bigger the phenomenon, the more difficult this chain was and times were measured in centuries, if not millennia or even more.
A striking example of this precept were rivers. They did not move randomly, but followed a very definite path. And in doing so, they changed that path. Year after year, the constant force of the water dug deeper and deeper into the ground, creating a deeper and deeper riverbed. It was an extremely slow process, of course: the water had to carry millions of stones for thousands of kilometers before the change became significant. But still, over the course of a few decades, it could be seen that the shape of the river had modified a little, even if the changes were so small as to be almost invisible. The newcomers were aware of this and in fact built their ports and their river cities using specific levees and creating water systems to prevent the river from becoming too low or too high at that precise point. Even if it was only a few centimeters, it was still dangerous and it was advisable to take the necessary precautions.
But what if the river instead had more time? What happened over thousands or even millions of years? The answer was simple. The river would keep digging, day after day, year after year, century after century. The ground would have sunk more and more, but once a certain limit had been reached, the walls would have collapsed due to the friable and muddy material of which they were composed and would have filled the river bed again, lifting it again. But what if that didn't happen? What if the river had instead passed through very solid ground, such as rocky heath? In that case the walls wouldn't have collapsed, because the material of which they were made would have been hard enough to keep them stable. The river would have dug more and more, until it sank several hundred meters. Eventually, it would have formed a gorge. A gorge like the Arapaina Gorge.
Haku had suspected it ever since Zamor had first told him about it. Indeed, how could a gorge be formed by walls as smooth as the lizardman described them? Any other natural event such as an earthquake would have left deep cracks in the rock. Confirming his suspicions was the shape of the walls: not only were they perfectly smooth, but on them many could see signs, similar to waves, which had given the gorge its name ('Arapaina' in the beastmen meant precisely 'waves of rock'). Even legends were born about these marks, but obviously Haku wasn't fooled by any of them. Those marks could have been left by only one thing: the powerful erosive force of the water.
But then the question that arose at this point was: what happened to the river?
The most obvious guess was that it had dried up, but Haku didn't find it very convincing. Zamor had described the gorge very well, and so Haku knew that its base was almost perfectly perpendicular to the walls. If the river had dried out over time, the land would have had a more concave shape. Instead it seemed that it had suddenly disappeared, without a trace, as if someone had lifted it and carried it away. But that, of course, was impossible. Haku was sure there was an explanation... and Darbi had given it to him.
Darbi, Brenno, Gord and Isaac had carefully explored the whole area near the Kotenka River, to know exactly where to take the ships, and there they had found several caves from which underground rivers flowed and poured into the Kotenka. And one of these rivers was in just the right spot, exactly paralleling the Arapaina Gorge far to the west. The sending of some scouts in the area had resolved any doubts: they, carefully exploring the old course of the river, had found a spring which, however, poured into a crack in the ground a little further on. At that point everything was clear: the ancient river had not dried up at all, it had simply created a new path under the surface of the earth. The waters must have dug more in a point where the soil was more friable and had penetrated underground, creating a huge tunnel that passed under the ancient river. That tunnel had become bigger and bigger until the ground had given way and the small tunnels that had allowed the water to penetrate underground had collapsed, creating a gigantic fissure, through which all the water of the river poured underground, leaving the his ancient bed in the sunlight preferring the darkness of the caves. And so, the Arapaina Gorge had remained dry, while the river had continued to exist just a few meters below it. A quick scan of the land by Maldor with a spell had confirmed that several tons of water flowed under the gorge every day.
And Haku, of course, knew exactly how to use that to his advantage.
"Are you nervous? You're shaking a bit"
Isaac and Maldor (she in her avatar) were inside a large cave in which a river at least ten meters wide flowed placidly. The ceiling was very low and the only source of light was a torch that the man was holding in his hand. "What do you say? I'm about to raise a river, be hit by a hellish temperature and then be buried by thirty-five meters of rock. I'm very calm" Isaac replied sarcastically, who was trying in every way not to notice the sweat on his forehead.
"Don't worry, you won't die. We've prepared for this" Maldor said, placing a hand on his shoulder.
Isaac seemed to become calmer at the touch, but he still continued to shiver slightly. "Maybe, but I'm still anxious!"
"Wow. Who are you, and what have you done to the brave Isaac who hid the identity of a dragon, started talking to her in the middle of a battle, chased her, chose to stay with her in spite of the risks and then infiltrated with a lizardman, a minotaur and another dragon in enemy territory?" Maldor asked sarcastically, though some of her cackle was genuine.
Isaac puffed out his chest. "He's still here, of course! He's just calculating the risks well, just like he always has! But still, he's going to prove his mettle yet again by ignoring those risks and acting for the greater good!" he said proudly.
"This is talk!" Maldor answered, though he didn't refrain from bursting out laughing. Isaac looked a little offended, but he finally laughed too.
But this ilarity was soon stopped by a voice. "Do you mind? Our brother is speaking at a legendary level right now! Move instead of talking!" Sisna exclaimed, with Malchia's assent, then she looked at Isaac and said: "If you're nervous, I have a calming potion. Take it and do your duty instead of wasting time"
Maldor and Isaac fell silent. Indeed, Sisna and Malchia were right: this wasn't exactly the moment to waste time.
The four of them had split from the main army about a week earlier. Haku had sent them to the source of the river, where the water went underground, and they had gotten there easily and inconspicuously thanks to the invisibility rune and their avatars empowered with feline paws (Isaac had strapped himself on Haku's back Maldor). Once there, they had entered the tunnel and reached the gorge from underground. They were now perfectly below the Arapaina Gorge, and were ready to carry out their part of the plan. Maldor and Isaac had continuously scanned the ceiling to sense the arrival of their comrades, and so they knew that Haku had already started it all. Now it was their turn. "Okay, let's get started" Maldor said. "Sisna, Malchia, get ready to change your clothes. Isaac and I will take care of the rest"
"We're already ready" Malchia replied proudly.
"Very well. Isaac, do you want to proceed?" Maldor asked. Isaac nodded and stepped forward, then raised his arms and said a long spell. It was one of the most complex spells he had ever used, and anyone below the level diamond would fail to use it. When he finished reciting it, the water rose. The whole river rose up until it touched the ceiling and began to press against it with force creating some cracks in the rock. Obviously it wasn't all the river: it was only a small part of it, about fifty meters long, but lifting it was still a very tiring and difficult spell; Isaac had to call upon not only his mana, but also what he had accumulated in various magical items he kept on him. In fact, the water not only had to rise, but also stop flowing and remain in one place (since only a piece of the river had been raised, the water soon reappeared below it and continued to feed the river).
Once the spell was completed, Maldor opened her dimensional bag and extracted several potions which she tossed into the water. These were potions of poison combined with dragon blood. In few seconds, the water had become no different than acid. "Now comes the hard part" she said. "Did you activate all the necklaces I gave you? If you didn't, your bodies will be charred instantly"
"Don't worry, I did it ten minutes ago. You guys can't die, but I don't have an avatar! I care about my life!" Isaac answered.
Sisna and Malchia nodded too. The necklaces Maldor was referring to were powerful magical items he had created using a combination of runes and the knowledge he had acquired at the Magic Academy. They contained a powerful heat protection spell; against what Maldor was about to do it would only last five minutes, but that was enough.
Maldor raised her hands and chanted a spell of her own. Her too was long and complex. When she was done, a flame shot up in the center of the cave and expanded into a ball of fire at least two meters wide, emitting a light so powerful that it was brighter than a thousand suns. If Isaac hadn't previously cast a protection spell on his eyes, they would have exploded inside the eye sockets from too much light. Maldor, Sisna and Malchia had no such problems (since the eyes of their avatars were already dead) but still they sensed the intensity of the light. In an instant, the cave's temperature skyrocketed, so much so that the rock get red-hot and then began to melt.
Several tons of water vaporized in an instant due to the enormous heat, but they had no chance to escape: the ceiling blocked them and Isaac's spell kept them there. The man, seeing what had just happened (or rather, sensing it since it was impossible to see anything because of the light), intensified his spell even more, calling on every mana pool and every ounce of energy he possessed, compressing the vaporized water even more. Squeezed by the enormous pressure and continually heated by the intense heat, the water continually changed from a liquid to a gaseous state until the ceiling began to shatter. The rocks, already made weaker by the temperature that hit them, split violently under the intense pressure of the water that desperately tried to escape from the infernal temperature. Larger and larger boulders began to collapse, many of them melting as they hit the ground, until the ceiling literally exploded.
As soon as she saw that the rock was collapsing, Maldor extinguished her fire spell and grabbed Isaac, then she created a magical protection that enveloped both of them and threw herself into the boiling water that was splashing upwards. Isaac, on the contrary, didn't stop keeping his spell active and indeed continued to increase the pressure on the water, making it run faster and faster upwards. Malchia and Sisna, on the contrary, looked at each other and then threw themselves into the water, without any protection, and when they were a few meters from the surface they extracted something from their dimensional bags.
In the Arapaina Gorge, everyone suddenly began to feel something. At first it was just a strange sound of flowing liquid, sort of a 'blup'. But then that sound became more intense and the ground began to shake more and more violently. The human soldiers were somewhat confused and looked at their feet; the amphitrites, sensing danger, took to the air without the permission of their riders, and so did the wyvern of Carrion, who had remained quiet until then. The beastmen, by contrast, were quiet; where they stood the earth was still shaking, but not as violently as it does with humans. "It seems that Haku's plan is working" Zamor murmured with a small grin.
An instant later, the ground cracked and a jet of boiling water shot upward, with such force that it reached at least a hundred meters in the air before stopping. Some of the water was already vapor, but most of it remained liquid due to the intense pressure. Then a second jet split the ground. Then another. Then another one. Finally, the ground literally exploded under the feet of humans; a gigantic jet of water about ten meters wide and almost as high as the walls of the valley emerged with unprecedented violence. Maldor and Isaac, swept along by the force of the water, were hurled skyward as if thrown from a catapult; when they were far enough away, Maldor summoned a wind spell to hang herself in the air and so did Isaac, then they quickly flew towards the beastmen army as disaster struck below them.
The entire human army was literally run over by the jet of boiling water. Any person below the level iron died instantly from the power of the liquid which reduced their bodies to literally crumbs, and those below the level gold died within seconds from the intense heat which cooked them alive. All the survivors, even the strongest, suffered very serious burns, but despite this they were still able to fight. Using their strength, they avoided falling into the huge cavity that had been created and returned to the stable ground, which however was rapidly filling up with water that continues to leak from underground. In addition, all of them immediately felt weaker from the effect of the poison, which they couldn't help but ingest when they were hit by the water.
The flying animals managed to avoid the boiling water. Carrion's wyvern began flying towards its master, but suddenly a long, serpentine shape emerged from the hole along with the gigantic amount of water and leapt towards the animal, coiling around it and pinning it. "You're not going anywhere!" the huge snake said with the voice of Sisna biting the wyvern's neck. The animal tried to free itself, but a second giant snake emerged from the ground and bit the wyvern in turn. An abnormal amount of poison quickly entered the circulation and paralyzed the limbs of the wyvern, which fell to the ground unable to move. The two snakes took advantage of this and broke her neck, killing her. Then they swam back to the jet of water and used it to propel themselves upward to catch the amphitrites.
The surviving soldiers were speechless. "Basilisks?" an officer exclaimed recognizing the animals. But it was absurd… those basilisks were far too strong, since when could basilisks kill a wyvern? And since when did they act in pairs and in such a coordinated way?
In reality, the two basilisks were nothing more than two avatars, who at that moment were possessed by Sisna and Malchia, who had pulled them out of their dimensional bags as they were carried away by the current. These were the dead bodies of the two basilisks that the dragons had lured near their secret camp to ward off the curious; before the army left they had killed them both and then made some changes. They had used adult dragon blood to increase their strength, had covered their bodies with runes to make them resistant to heat and pressure and to allow them to grip more tightly, and had enhanced their venom with more dragon blood and different magic potions. Now, Sisna and Malchia were possessing two real monsters.
"Quick, grab your weapons! Point them at... UUURGH!" an officer tried to give orders, but his throat was pierced by an arrow, killing him instantly.
"Don't get distracted, humans. We're here too, don't forget it!" Zamor exclaimed holding high a bow, and then he yelled: "Archers, shoot!"
In a second was heard the crack of hundreds of bows, and then a shower of arrows descended upon the enemy army. Many of them were enchanted and exploded as they struck their victims. The soldiers, already debilitated from burns, water and poison, had no way to react. Many of them fell lifeless to the ground, while the two basilisks continued to attack the amohitrites in the air. Some of them tried to flee, but Maldor and Isaac, along with other spellcasters, used very powerful spells against them from above, while holding themselves up by the magic of the air.
Just a few minutes after the start of that battle, the winner was already clearly marked.