On approach to their chosen planet they'd been approached by another. Larger, but singular to their pair. Possibly able to take both of them and win, but possibly would fall to their superior numbers. Basic long-range communication had been established, an offer of exchange given.
The offer had been refused, and instead the other had ejected a single shard in their direction. A pitiful little thing, barely worth the effort. It was collected, isolated, and examined anyway, containing nothing but a warning that they should avoid the planet they'd chosen at all costs. That those who inhabited it were too dangerous, flying in the face of their own analysis of the world.
They'd ignored the warning as the other left without any further communication. Deployment of shards and tweaking of the cycle parameters had happened without issue. Protections for the host species finding out what they were, their true origin and purpose, were implemented. Shards were spread out on the predetermined patterns needed for maximum resource collection during the cycle and the two had safely landed on their chosen instances of the planet.
There was no resistance as they settled in and formed their avatars for this cycle, no sign of any trouble, and they stepped through to the world they'd chosen without issue. None saw them arrive, and they moved to blend in until shard connections had reached minimum saturation level to begin the cycle proper. Except they'd been complacent and didn't know that things had already gone horribly wrong.
No host species had detected the monitoring connections in the first tenth of the cycle before. How could they, without the benefits of the full connections aiding them? So there were no provisions for information leaking before full connections were established. Worse, there were none for the host species discovering and tracing the monitoring connections before the avatars arrived on the chosen primary world.
But this species had, and had secretly established communication with other instances of themselves once they'd figured out that the monitoring connections led to other dimensions. By the time the avatars had arrived the fact that an alien something was invading was common knowledge among several governments, kept secret to prevent the aliens from finding out they'd been discovered.
Worse, the avatars were made out as not being of the host species within hours, but hadn't realized that they'd been identified. They were watched closely as they waited for connections to be established, happy when they did but missing when those connected to vanished. But many with sudden power would hide to consolidate it before revealing themselves, and the cycle parameters would ensure that the latter happened eventually, so that was ignored.
It took them two orbital cycles of the planet to realize that something was wrong, that there weren't enough connections and nowhere near enough conflict. By then it was far too late. The host species had somehow reached every shard they could find and suborned them, using those capable of it to aid them in suborning others. Many were actively being dismantled for information while others were used to prepare to defend all instances of the planet they could.
The first warning that they'd already lost was when the one specialized in analysis had been taken out. One moment there, the next their avatar was gone. Only later would the remaining of the pair determine that trying to check on a shard to see why it was dormant had caused it. That would only be learned when it did the same, only for the information to serve it no good as it was taken over and shut down before it could so much as consider attacking.
Ten orbital cycles of the planet later it, and many of its dimensional counterparts, would start to send out interstellar spacecraft. To explore, expand, and hunt, for where the first two came there were almost guaranteed to be thousands, millions, possibly billions or worse more out there.
One pair had come for Humanity, another had opted to start running before it had ever reached a version of the planet that Humanity called home. That one got just over a decade and a half head start, but now it was being hunted, along with the rest of its species...
