Disclaimer: The following is as much science as I am an iguana-walrus hybrid with scantily leather-clad leprechaun slaves. Which I'm not. Just to make that clear. Also, don't own it.

Apologies for the delay. I was away for a bit over a week and forgot to put notice in the last chapter. This should be the last such delay for some time.

(Train-sitions, a.k.a. train stations. This was funnier in my head.)

Catalyst

The Queen was the first to awake. It had started as minor discomfort, an ache in the muscles, minor twinges in the thorax, nothing to be alarmed about, and nothing that could not be endured. But it grew, spreading throughout. Soon the ache was everywhere, stretching from her legs to her antennae, every part of her body screaming in pain. The Queen's children rushed in, desperate to defend from this foe, but found nothing. Still, whatever this malady was, it continued to grow. To her mandibles and eyes, until it eventually reached her thoughts. It twisted them, breaking them and pulling them apart. It was in this space between her thoughts that the Mind arrived.

(Transition)

Abathur's train ride could be summed up very easily as dull. Most of his time on the terran vehicle was spent reading his textbooks while making small talk with Hermione. It was a concept Abathur had fundamental difficulty with. Certainly the exchange of information was valuable, but most of the conversation was superfluous, unnecessary; it was incredibly unimportant what book was read where, or the color of an unnamed relatives fish. Unfortunately, it appeared to be a necessary part of human interaction.

Oddly, neither Harry nor Ron arrived, which was unexpected, but viable. Hermione was the most useful of the three in most commonly encountered situations, being most familiar with psionics. The reduced amount of camouflage was risky but adequate. Of course, perhaps they had merely taken an alternate route. No conclusions could be made.

Eventually, the ride came to a close. Abathur stepped off the train, walking over to the carriages pulled by the interesting looking equine organisms. Something in its essence was quite odd, and Abathur considered consulting his books for a description. He was just setting aside his trunk when he felt it. The virus had borne fruit.

(Transition)

The Mind reached to and through the Queen, shaping her, molding her. It took away the pains, replaced them with strength, it took the aches and made them more. It shaped and grew her thoughts, teaching her of concepts that were previously inconceivable. It taught her of the stars, of the Swarm in all its diverse forms, of the many that were one. It told her of essence, that was contained within her, that was within all. It taught her of tactics, of war, and while she understood only part, the Mind deemed it enough. It told her of it's plans for her and her colony, and of those beyond.

All the while, it shaped her, changed her. Into what, the Queen did not know.

(Transition)

Abathur spent the rest of the evening with only half a mind focused on his surroundings. He had exited the carriage and walked up the steps in little less than a mobile stupor. He listened to the song and the sorting following it only in the technical sense, sparing no attention to the terran ceremonies. All his focus was spent on the ant queen, molding it as best he could from this distance, allowing the creature to improve itself later. Already, he could feel its presence in a hive mind, see through its eyes from hundreds of miles away, even after being alone in thought for over a decade. He continued to spin strands as he ate the meal, as light fled from the sky. Abathur didn't bother sleeping. There was work to be done.

(Transition)

The Mind stayed with her for hours, shaping her body and essence. The Queen's mind expanded, no longer limited to its cage of flesh. Her limbs grew strong, her eyes saw the world anew, everything became more. At last, the transformation was complete, the Queen free to move. But the Mind had tasks for her, more plans.

It had her gather her children, to order them to gather massive amounts of food and flesh. They gathered all that was living, and some things that had been. Bark, twigs, beetles, nothing was to be passed over. The supply lines covered the log containing the colony with a sea of black carapace. The harvest was placed in piles throughout the colonies tunnels. When the Mind had determined it to be enough, it ordered the Queen to gather her children once more. Every last one of them.

(Transition)

The problem with the hyper-evolutionary virus, Abathur mused as he walked the Hogwarts corridors, was that, without a specific goal, it had a tendency to churn out ill-formed monstrosities that were almost worse than their starting state. The infested terrans for example, were slow, frail, and low damage. It was a standard reaction to introducing the virus to large populations without a template, the result was half-formed, short-lived, and pathetic, useful only as cannon fodder.

But with the right oversight, or a specific goal, the virus was a powerful tool to weave essence. It could turn a population of any species into fully fledged zerg in little time. It could create new strains in less than a day. Abathur had made frequent use of it, and would likely continue to as necessary.

Of course, you still had to have a way to spread it, and the resources to make it viable.

(Transition)

Through the Queen, the Mind ordered her children to dig into the mounds of food. The ants dug through the piles in droves, entombing themselves within. The Queen herself moved around the piles, spraying each with a fine green mist. The colony all but vanished into the mounds. The rows of mounds extended throughout the entirety of the colony, filling the caverns to the brim. All of the ants, all of the food, just sitting in wait as the Queen wandered, and the Mind watched.

(Transition)

Abathur was in charms when the preparations completed, right as the class was wrapping up. Despite his eagerness to begin, Abathur waited. After all, History of Magic was next, and nobody would notice there if Abathur had abandoned attention by his body. At least, they wouldn't think about it.

It took barely a few minutes to reach the classroom, even if it felt far longer. Abathur watched the ghost in the front carefully as he walked to the back of the room. It had never expressed interest before, but it was still a thing of thought without body, without essence. An unknown variable to the extreme, and potentially very dangerous. When another thorough inspection revealed had confirmed its inattention, Abathur sat down and put his head on the desk. He closed his eyes and moved his mind. His body relaxed. Abathur did not.

(Transition)

Before the ant colony had been a focus of activity, the epicenter of the insects activities. Now, the only thing moving through its creep covered caverns was the massive body of the Queen, moving through the pulsating structures. Previously just bits of bark and fruits, the throbbing tumorous masses dominated the tunnels. Embedded in the mounds were countless former ants, each encased in a translucent, green tinted cocoon, each containing half finished, twisted flesh. The Mind lurked over the mounds, observing, altering, shaping the strands and sequences within. Already its work was evident. Through the murky liquid, the Queen could see sharp, elongated jaws, legs varying from two to twenty, bodies filled with liquid, sharp spikes jutting from thoraxes. It gave the impression of some mad scientist's lab. No two were quite the same, traits seemingly randomly grafted onto each, yet there was an impression of convergence, of all the creatures moving towards a common goal. For now, the creatures stayed still, inert within their cocoons. But here and there, a limb twitched.

(Transition)

Despite all signs pointing to simple sleep, Abathur was deep at work. The ants within each cocoon were being molded, their essence very versatile. Abathur was experimenting with each and every specimen, determining the most efficient result. It wouldn't take too long before he was ready to unleash them once again, the creatures were nearly complete. Even as the ghost recited long gone events to a comatose audience, Abathur spun and wove the strands and sequences, looking at the insects' flesh and seeing only potential. Before, they were meagre. Abathur would make them great.

(Transition)

All throughout the hive, there was a sudden rush of activity. Cracks were forming throughout the cocoons, claws and jaws snapping at their prison. First one, then two, then dozens at a time emerged, scrabbling over each other, finding their places in the tunnels. Each was a monstrosity, a composition of sharp jaws and rigid carapace bearing little resemblance to the ants they were made from. The hive mind grew and spread, connecting and binding each. If the Queen had had lips, it would have smiled. The Mind watched, impassive, but even it had a taste of exhilaration in its thoughts. When the last cocoon broke, and the last newborn Zerg emerged, the last piece snapped into place. The ant colony was dead. Now, only the Hive, ready to spread and change, was left.

Lurker: A specialized creature, Lurkers are powerful subterranean attackers that can easily turn the tide of battle. Morphed from hydralisks with the assistance of the lurker den, lurkers are unique both in that they can burrow without research, and can only attack when burrowed, shooting a long line of spines that do massive area damage. It is one of very few creatures able to attack underground, the only others being banelings, swarm hosts, and infestors. Lurkers are used somewhat like the zerg equivalent of siege tanks, setting themselves in defensive positions, or slowly pushing them forward by burrowing and unburrowing repeatedly. When in the right position, lurkers can decimate armies of lighter units in an instant, or do heavy damage to the more durable ones. Due to the long time it can take to get Lurkers on the battlefield, they aren't commonly deployed, but when they are, victory is almost assured.