UnacquaintedLove
For millions of years humans assumed they were the only living things in the universe. Then it narrowed to their Galaxy. But humans wouldn't be able to comprehend what was really out there, what other organisms live out there. On other planets, in other galaxies. Like, The Alpha Centerial Star System, holding a planet humans would otherwise consider science fiction.
Cybertron.
Nothing good ever does.
The cube.
So when their planet died, and Opitmus sent his best scout to find it, entrusting him with the last known signal of the cube. And B-127 chased it to Earth. And he found the boy who held all the answers. And they got their answers.
They got the cube.
And they killed Megatron
Or so they believe.