Tristan let out a relieved sigh as he secured the last of his tools. With all the items needed to fix the portal device now safely stowed away, the young adult turned his attention toward a more interesting target - the cactus forest in the distance.

Tristan wanted to get home as soon as possible, there was no doubt there, but the circumstances of his accident allowed him to experience something that not even Nigel had attempted - an insight to the next chapters of the story of life. He was in a world that existed (presumably) after mankind had vanished. So what was that world like? What psecies had we pushed toward extinction, only for them to bounce back in our absence? Were there new groups of intelligent primates, ready to take our place? Would new sapient creatures evolve at all, or was mankind a unique situation, if perhaps only on Earth? All these questions and more, Tristan wanted answered. Preferably sooner rather than later.

Thus, with his camp safely secured, Tristan offered Terence a morsel to eat before heading off toward the cactus forest, soon followed by his titanic tyrannosaur companion.

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The spiders tended to their webs, ignorant of the world around them. Those filled with food were targeted first, cleaned out by the workers until all that hall was edible had been paralyzed and moved to the 'pantries' of their nest. Next to be tended to were those that were damaged by winds and debris - those that could be salvaged were repaired, those that could not were devoured to recycle the silk. Occasionally an insect would become entrapped by one of the broken webs, leading to a ferocious mob of arachnids moving to subdue the victim before it broke free. Last to be dealt with were the seeds that had become embedded in the webs, carried their by the wind. Some were discard, others piled up at the base of the webs.

Soon, movements below turned the spiders' attentions toward the ground. There, a group of mice had gathered, eyeing up the seeds. When they became aware of the spiders' presence, a group of beetles were deposited next to the seeds. The spiders examined this mass of armored arthropods for a moment before digging in, while the mice snatched up the seeds to take back to their burrows.

Such was the way things had been, such was the way they would always be. Regardless of the looks that the strange bipedal mammal was giving them.

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The giant Gila monster retreated into its burrow, the remains of a peccary in its maw. Only once it was in the center of the underground shelter did it begin to feed.

Nearby, a terror-bird like creature eyed the carcass, as well as the lizard. Realizing that it was being watched, the reptile let out a submissive hiss, one that the bird heard loud and clear. With only a moment of hesitation, the bird stood up, snatched a limb from the carcass, then retreated back to its mound, taking a moment to examine the ovals within before it sat back down.

The male giant road runner was careful to ensure that none of the eggs were damaged before it returned to brooding - losing even a single egg would enrage his mate. Once those eggs had been checked, it turned its attention to the leathery eggs beneath them - each was still developing normally, to the bird's relief. The reptile it shared its burrow with was very protective of those eggs.

As the last pieces of the peccary leg disappeared down the bird's throat, it promptly stabbed its beak into a nearby cactus root. The bulbous water store burst open, rewarding the bird with a refreshing gush of liquid. Soon, the reptile joined in, chewing on the exposed, succulent plant flesh. Water was a rare commodity, and one that desert creatures could not afford to waste.

The carcass lay where the lizard had left it, surrounded by other corpses. Soon, it was joined by the empty husks of beetles, brought there by spiders that had just picked their webs clean. Occupying the spaces between the stems of the cacti, these webs provided plentiful food for the arachnids, though they served another purpose as well.

When the spiders had left, giant bark scorpions made their move. Some dug into the beetle carcasses, while others began to move the more desiccated remains into a tunnel, following the roots inward. No resources could be wasted here, least of all meat.

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The giant rattlesnake watched as the hawks took flight, searching the skies for a meal. Nearby, the frogs retreated into their ponds, waiting until the sun set.

Briefly, the serpent searched the upper perches for birds to devour, but when none materialized, it began its descent.

Along the way, it passed turtles and sheep, all trying to eat the few plants that grew here. Rats and mice gave it a wide berth, though the only one it did devour was already dead, and from a rival nest at that.

Yet that one stop left the snake utterly stunned when two strange bipeds emerged from behind a group of rocks - one looking like a feathery lizard, the other a bald mammal.

Neither group moved for a good minute, before the snake darted into a tunnel and continued its descent. Now, it passed by frogs, lizards, other snakes, ants, and scorpions, but it paid them no mind until, at last, it had reached its destination.

Said destination was a cool tunnel located deep beneath the earth, where an underground stream flowed. Cactus roots descended into the water, drinking up as much fluid as possible.

In another room, carcasses littered the ground. Fungi took root on these decaying corpses, rendering them down into material that plants could absorb. Nearby roots ingested this fertilizer, allowing them to grow even in a land so barren of resources. Moving to and fro were a mixture of scorpions and ants, each species carrying something different - the scorpions deposited new carcasses in the rooms while the ants instead added water, which helped to keep the fungi moist.

The fungi sustained the plants, who in turned sustained the animals - either providing food for the leaf eaters, or shelter for the carnivores. That was how things were, what they are, and what they shall be.

And all of that was why everything living amongst the cacti got along, for the most part.

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It was roughly two in the afternoon when Tristan and Terence returned to camp. The tyrannosaur was mostly happy just to be back, but Tristan was...confused, to say the least.

He had just walked through a forest made of cacti. That, in and of itself, was not surprising, for cacti could get fairly large. What had surprised him, though, was the massive number of animals in said cacti, many from different species. Some were predators of the others (at least, he presumed), yet none did anything to inconvenience each other in the slightest. Why?

A rumble from his stomach dashed any further thoughts about this conundrum from Tristan's mind, though. Thinking on an empty stomach was not a good idea. Heeding his belly's advice, Tristan walked over toward the makeshift pantry and opened it...

...At which point an eight-legged creature jumped out.

It was a camel spider.

One that was...well, about the size of Tristan's shoe.

For a moment, Tristan said nothing, before promptly letting out a shriek and trying to whack the arachnid with a nearby log. Surprised, the arthropod retreated toward the portal storage tent, narrowly avoiding one of Terence's feet as it did so.

Its luck ran out, though, when it tried to seek refuge in the tent, for when it did, the creature ended up colliding with the portal device, which quickly began to come online. Tristan and Terence both let out a groan when the activation noise started up, knowing that trouble was coming.

A minor shock caused the arachnid to fall into the sand near the tent. Soon after, the device whirred to life, with an exposed wire promptly shooting off a larger bolt of electricity at the downed arachnid, who's body was not only burnt to a crisp, but also exploded, leaving a smoking pile of flaming arthropod sludge in the sand.

Tristan and Terence barely paid any notice to this - their attentions were now focused on the active portal...from which they could hear a familiar trumpeting sound...

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AN: Yeah, things get weird here.

Just a quick note, but while I may explore the topic of artificial evolution later, the cactus city and its inhabitants are 110% natural.

So, Read and Review! This is Flameal15k, signing off!