This is mainly set in the cartoon continuity, sometime after the movie. I'm ignoring the whole return of Optimus Prime story.
In the movie, Unicron is shown creating 3 Sweeps and 2 Cyclonuses (Cycloni?), and afterwards, they usually show 4 Sweeps and 1 Cyclonus. So anyway, as far as I'm concerned, Thundercracker=Cyclonus, Skywarp=Scourge, the Insecticons=the Sweeps.
Dawn. On the planet Xaavonce, dawn was a beautiful sight to behold.
Although Xaavonce had an extremely advanced society, the populace shunned technology. After decades of warfare, the Xaavonese people finally achieved peace. Feeling that technology had been the cause of the war, they decided to put technology aside, and return to more traditional, peaceful ways, the ways of their ancestors who had evolved from the reptiles. As such, there was very little pollution in the atmosphere, giving an unobstructed view of the sunrise.< p>Sub-Commander R'tahok of the Northern Defense Force admired the view, as the the light reflected off the moons, and then disapeared from the visable spectrum. R'tahok was one of the few soldiers from the old war who still lived, the others having succumbed to ravages of time. He remembered the horrors of war, as hatch mate fought hatch mate. But that was a long time ago, and he was little more than a hatchling then. Now he was a veteran, and a respected member of the Defense Force. The Defense Force itself was also largely ceremonial. It gave the people a sense of security; if something happened, they would deal with it. Since the wars, the only time I've used my weapons was when I fought off a wild Igyak, he chuckled to himself.
The first to see it was a rookie, barely with all his adult scales. "Sub-Commander! Look at the sun!"
R'tahok was about to chastise him for his outcry, until he saw it as well. A large black mass moved across the sun, and it was getting larger. "I've never seen anything like it..." he said, aghast. It was no cloud, no eclipse. And it was approaching the planet.
It landed a few miles south of their position, and immediately began devouring everything in its path, leaving only a flat wasteland in its wake.
"Sub-Commander! What do we do?" the rookie said.
"Make your peace with the gods." was all R'tahok could think to say.
Maybe if they had technological weapons, they could mount an opposition to these invaders. Maybe they would have been just as doomed. It didn't matter, as their bows and spears were having little effect. R'tahok finally got a good look at them, as his unit was consumed. They had the appearance of giant skulls, with tendrils extending out their backs. They left a trail of mist that was as black as their bodies, which seemed to phase in and out of synch with the physical world. Why? We returned to the old ways! Why would the gods allow this? was R'tahok's last thought as he too was consumed by the aliens.
In all, it took 33 hours for the invaders the cleanse the surface of Xaavonce, taking it's plants, it's minerals, it's animals, it's resources, and it's people. The planet was now an empty husk, which would eventually fragment into asteroids.
And so the Swarm moved on, looking for a new world to consume.
Chapter 1
Cybertron: 2007
Dawn. On Cybertron, dawn had little meaning. With the planet almost entirely covered with technological cities, one was able to find adequate lighting almost anywhere. Anywhere that is, except for the Preserve. The Preserve was founded early in Cybertron's history, so long ago that the details have been lost in time. It's purpose was to maintain an area of 50 square miles in the planet's original state, it's state before the times of Primus. It was just about the only place on the planet where vegetation could be found. The Dinobot known as Swoop came here often to watch the sunrise, as this was the only place he could view it unobstructed. During his time Earth, Swoop and the other Dinobots learned to appreciate it's natural beauty more than most other Autobots, possibly because they were the first Autobots constructed on Earth, and the first based on animals.
As he admired the sunrise he thought, Snarl would have loved this, remembering his comrade who died in battle against Devastator, a year before the coming of Unicron.
The sunrise complete, Swoop jumped from the tree he was perched in, and began flying towards Iocon, the capital of Cybertron.
Swoop shuddered briefly as he passed through the special energy shield that existed to protect the Preserve from Cybertron's harsh environment. A case in point: just four miles from the Preserve was a melting pit, one of many created after Unicron's coming to convert the shattered remains of the sector Unicron attacked into new building materials. Although the thick smoke made it somewhat difficult for Swoop to see, he was able to make out the form of Kup, who was supervising the operation at this pit.
"Okay now, just a bit more to the left. Drop it... now! Good, move over to..." the old Autobot instructed a construction droid, as Swoop interrupted him.
"Kup! When you tell Swoop war stories?" Swoop asked. "It been nearly a month since you tell Dinobots story!"
Kup, trying to conceal his annoyance, "I don't have time for that now. This is the first lull in fighting we've had in months. I don't know when there'll be another chance to work on the reconstruction. I'll tell you what. As soon as Cybertron's repaired, AND the Decepticons have been defeated, I'll tell you as many stories as you want."
"But Swoop want hear story now!" he pleaded.
"Why don't you go bug Hot Rod! He's Prime now, I'm sure he has plenty of good stories." Kup said, trying to find a way out.
The Dinobot considered this a moment, and finally decided it was the best he was going to get. He once again headed for Iocon, and was surprised to find that he was recieving an A-1 priority message.
The message began, "This is Rodimus Prime. This message is being routed to several Autobot warriors, and I request that you make your way to the Citadel for an emergency meeting. End transmission." Although he was already heading in that direction, Swoop transformed to robot mode for greater speed and headed for the Citadel, the seat of Cybertron's power.