City of Sin Book 4, Chapter 48

Undead Scouts
The same evening that the summoning formation was completed, Rosie quietly packed all her tools and headed back to the city proper alone. Nyris, Agamemnon, and Richard stook together, watching as her figure disappeared through the gates.
“I’d never known this beauty had such a side to her. She’s quite something!” Nyris praised.
“Indeed,” Agamemnon answered in agreement, a rare occurrence.
Even Richard had to admit that Rosie’s ardour was hard to come by. This sort of pure focus couldn’t be explained just by personality; she had to have great motivation in some areas. This was similar to Richard himself, who had spent five years studying like the madman with a single image burnt into his mind. Just like Elena’s fiery end, Rosie’s quiet demeanour hid some powerful purpose, a sort of zealotry that guided her to a goal.
“Hey, Richard!” Nyris suddenly hooked his arm around Richard’s neck, his slender arm suddenly as tough as steel, “Listen up. From now on, Rosie’s officially one of my friends!”
Although the chokehold almost left him unable to breathe, Richard felt like it was hilarious. This wasn’t the first time he was making himself a friend of the girl. However, when the prince loosened his grip and spoke once more, the next words left him unable to laugh, “Richard, Rosie isn’t any easy person, but she’s a good woman. Don’t give her the chance to betray you!”
Richard had to carefully think over these words. They were something he agreed with; you didn’t test the people you loved, you cherished them so much there was no chance of betrayal.
……
With the undead summoning formation finally complete, Zendrall finally started it up the very next day. On most planes the ceremony would need to be completed at night, but in the Forest Plane where the skies were perennially clouded over there was no such need. This formation took an enormous cost to operate, consuming fifty magic crystals every day. However, that only left everyone full of anticipation.
As the magic crystals lit up one after the other, a ball of grey light gathered atop it. A pale mist started spewing out as threads of cold, dark energy gradually spread through the area. A moment later, the first undead creature walked out of the newly formed portal. It was a lich!
Thankfully, the lich only acted up for an instant before it was suppressed by the power of the formation, brought under the control of Zendrall despite being higher in level than him. It floated out of the formation and started summoning low-levelled undead that were sent into the depths of the forest.
A skeletal horse then stepped out of the formation, ridden by a sturdy death knight. The death knight raised its heavy, rusted sword in Zendrall’s direction as a greeting, spurring on his steed in the direction Zendrall pointed.
One after the other, more undead beings walked out of the formation and submitted to Zendrall, heading deep into the vast forest. Within an hour the necromancer had six level 15 beings, about two dozen between levels 10 and 15, and hundreds that were weaker under his control. As these scouts left to fulfil their duties, Zendrall continued to keep the formation running. His soul force seemed immense, able to handle even more as undead continued to walk out one by one.
As they watched the mere level 13 necromancer control such a powerful army, everyone was rendered speechless; even Richard was seeing this for the first time. Those present finally understood why necromancers were so detested before the era of planar wars; if given enough time, those of other professions had no way of competing with them at equal levels. As he was right now, Zendrall could wipe out a full party of level 15 adventurers using his summons alone.
A map appeared atop the summoning formation, dull at first but being lit aglow as the undead continued to search. The misty and vague outline slowly expanded as more of the forest was explored, the results of the search projected onto the formation.
Zendrall sat patiently in the midst of it all, controlling the newer arrivals to target locations the original scouts had missed. Bottles of water and vitality potions were placed by him, with a fair amount of food for a long search. With a hundred-kilometre zone around the planar portal being protected from the will of the forest, the other two trees of life were quite likely more than 200 kilometres away from the city. Undead were not known for quick movement— the slowest skeleton warriors could only cover about five kilometres an hour.
It seemed like they would need two days at minimum to get any results. Richard arranged for a group of elites to protect Zendrall, returning to the city to continue his own work. A chilly breeze blew through the quiet forest, all sounds of life fading away as the little animals that roamed around hid away in their nests. A terrifying aura that they had never experienced before left them trembling in fear, only able to cower deep inside their caves.
The undead wandered around the forest endlessly, the ghastly flames flickering in their eye sockets making them terrifying as darkness fell. Specks of abyssal green light roamed throughout the forest, proceeding away from Emerald City. These creatures did not know fatigue, walking without end until their spirit fires burned out.
……
Deep within the forest, a pair of eyes focused on a skeleton walking in the distance. Quiet whispers moved along the wind, dispersed by the forest to avoid detection by the skeleton, “Elder, what is that thing? I sense unimaginable evil from them!”
“It should be an undead spirit,” an aged voice rang out, “This is the vilest creature that has ever appeared in our forest! It must have been summoned by those invaders. So abhorrent, the mighty will of the forest can do nothing against creatures without a soul!”
A huge bow was drawn on top of a tree with a flourishing crown, an arrow with nature energy twined around it aimed right at the skeleton. The archer looked young and strong, eyes filled with determination. “It may be evil, Elder, but it is not powerful. I can definitely kill it with one arrow!”
An old, withered hand pushed down the youth’s weapon, “No, impatience does not have its place here. We need to continue observing their actions. These creatures do not move fast, we will have ample time to make our preparations.”
The wizened druid gazed at the limping skeleton in the distance, “If we can find their true goal, we could perhaps set a trap here and teach those invaders an unforgettable lesson!”
……
As night passed and dawn arrived, Zendrall remained in position as he controlled the formation. No new undead were being summoned now, but there were already thousands roaming the forest. Lina, Agamemnon, Nyris and the others kept him company.
As it approached noon of the second day, they were now looking at the projection atop the formation with intent. The furthest undead knights had reached a distance where they could come into contact with a tree of life. Most of the forest was still covered in a mist, but there were thousands of small threads of light spread around everywhere that were slowly expanding further.
Everyone quietly awaited the results, but it wasn’t until night that Zendrall suddenly groaned, face paling as he said in a hoarse voice, “One of my summons was killed!”
“WHERE?!” Everyone immediately perked up.
The necromancer quickly gestured at the projection and enlarged one portion, showing a flickering red dot at the end of a line. “It was only a skeleton warrior, too weak to transmit what it saw before it was destroyed,” he explained, analysing the image for a short while before waving a hand to send a dozen creatures straight in that direction.
……
The low shrubbery of the forest was torn apart by metal hooves as a skeletal horse snorted icy wind, trampling through the thorns with purpose. The eyes of the death knight on its back were spewing a deadly emerald fire as it spurred the horse on at full strength, speeding forward.
The knight’s field of sight suddenly expanded as it charged into an expansive field. It quickly reined in the horse and looked upward, entire body shuddering for a moment. In front of it was a huge tree that was several hundred metres tall with hundreds of treehouses built on its trunk. The powerful aura of life emanating from the tree was like boiling hot oil as it touched the death knight’s body, spewing white smoke.
A tree of life!
The dense life energy left the death knight writhing in pain. A few rays of light quickly drew closer, mostly arrows imbued with nature energy alongside two powerful nature spells. Everything hit the knight at ones, covering it in a green fog that constantly burnt away its power of death. The undead creature roared in misery as the energy burnt it away, killing it off completely in the blink of an eye.