After many hours of underground exploration, the group finally seems to make progress... The numbers of Tunnelers they encounter had started to increase, as well as the variety of them. They'd already encountered the scout and warrior types, but they'd also fought against other, more specialised mutations.

The first one had been a smaller, more agile and sneakier variant, which had a limited ability to camouflage itself in a similar manner to a chameleon. Its scales were able to change colour at a slow rate to match the environment around it, allowing it to ambush from any longer it wished... At least, that's what would have happened had Bulwark's advanced targeting software not easily spotted them. ​​

Despite their stealth capabilities, the Chameleon variants were far more fragile than even the scouts, which made them easy picking for the Ultimo-Bot's flame throwers.

The next variant was one of the more dangerous ones... It had the ability to emit a poisonous gas from its skin. This wouldn't be too difficult to deal with outside, but in the underground tunnels, it was far more dangerous.

One wasn't a problem to deal with as the gas it produced wasn't enough to threaten anything, but a group of them? If not dealt with swiftly, they could make an entire tunnel uninhabitable... Fortunately or not, the only ones who were at risk of this were the Cyberdogs, as Afton, his companions, and the Ultimo-Bots were almost completely immune to it. Afton was resistant to all poisons even without his air filtration systems, and his companions had a big enough air supply to last for a day or so... Not to mention the Ultimo-Bots status as robots.

These creatures had toxic-green scales and looked moist to most eyes. Their mouths dripped with venom, and their claws looked more like needles than anything you'd see on a predator.

Last but not least of the mutations they encountered, were the 'Gargoyles' as Afton had not so warmly named them. They were slightly bigger than the warrior variant Tunnelers, but had much, much tougher scales that almost resembled rock in their appearance... Grainy and grey, Afton thought they wouldn't be out of place in a Dracula movie.

They had vestigial-looking wings on their back, as if they hadn't had enough time to make them functional, larger than average hands with matching claws, and a neck that matched the width of their heads.

They also seemed far stronger than the other variants, judging by their ability to easily tear apart any Ultimo-Bots they managed to reach. The only positive was their lack of numbers, maybe having only one for every hundred warrior variant, which, considering that Scouts outnumbered Warriors by the thousands, was very lucky.

By the time Afton's group reached a large cavern the seems to be some sort of nesting ground, they'd lost 20% of the Ultimo-Bots, and 35% of the Cyberdogs. None of his companions had been injured yet, but their armour had been nicked, scratched, and scorched slightly due to some unfortunate friendly fire caused by an Ultimo-Bot malfunctioning as it was torn apart.

Still, they had a large arsenal of missiles that could be used, and Afton wasn't above tearing the robots flame thrower fuel tanks off to use as improvised explosives... If used in such a manner, they'd be akin to napalm bombs, coating the surroundings in sticky flaming liquid.

The fight just to get into the cavern was hard enough, with around two thousand scouts attempting to block their passage. After that was thousands of workers who seemed to be part of their last-ditch attempt to halt them.

The reason for this was clear was Afton got a good look at the place... Large mounds of egg sacks were stuck everywhere. From the floor, to the walls, to the ceiling. Some looked to be fresh, not being bigger than an average person's head, but others looked almost ready to hatch at the size of an exercise ball.

At the far end of the cavern, he could already see the gathering Tunnelers attempting to try one last stand, presumably to protect their queen. There were no scouts or workers left, only warriors and gargoyles... That, and a couple hulking Tunnelers thrice the size of even the gargoyle varients.

They were half the height of an adult Deathcalw when on all fours, had incredibly tough-looking scales and seemed ready to tear them apart...

"Well, this is it... Fire your missiles!" Afton shouts, gesturing at the group of tunnelers.

The Ultimo-Bots do as they're told, streaming forwards and firing their weapons once in position. Smoke immediately fills up the cavern as the missiles fill the air, the cavern shaking once they impact the group.

*BOOM!BOOM!BOOM!BOOM!BOOM!BOOM!BOOM!BOOM!*

After a couple seconds of firing, they stop, waiting for any indication that their enemy had survived... Afton feared that sustained missile fire may bring down the cavern on their heads, which, while it would kill the Tunnelers, would also spell their doom.

"Flamethrowers, fire!" he shouts, wanting to see if fire would reveal anything...

Long jets of fire are released down the cavern, and judging by the screeching that occurs immediately afterwards, the Tunnelers weren't all dead. He activates his Infrared vision to see if he could see anything... He'd always thought that Tunnelers would be cold-blooded due to their reptilian appearance, but through their exploration, he'd found that the species could be both!

Some Tunnelers were cold-blooded, and others were warm-blooded... He had no idea how this was possible, but regardless, he'd try use it to his advantage... Unfortunately, he seemed to have underestimated their intelligence.

Above the entrance of the cavern that they'd entered from, Tunnelers were starting energy from the stone... With the smoke obscuring almost everything, this caught the Cyberdogs by surprise as they were suddenly assaulted.

"Guys, assist the Cyberdogs with the backline, I'll keep the side of things stable." Afton commands, having his companions go deal with the enemies emerging behind them.