The secrets of Delver technology could not resist decryption forever. While the tools they wielded are deeply weird, jealously guarded, and immensely complicated, living beings built the tools that brought aliens to the dragons' first world. The great calamity left ruins aplenty behind, and once grown the Seeker gathered these old tools as their very favorite sort of treasure. Dragons are not intelligent in quite the same way as a No-Tail, but they are far from stupid. They live forever and can be very determined if they set their mind to it.
The Seeker brought all its tools and treasure along with it when the world was evacuated ahead of the Tailless's relentless growth and hunger for resources. It studied under the great elder Darktooth on the new world, studied together with Darktooth (an arrangement not very common with dragons, as they are not particularly social), for a very long time. And eventually, by application of the hard claws of experiment and calculation and theorizing, the universe revealed its workings, cold and precise and mathematical. Creating more and more tools of the highest sophistication, and teaching others of its kind in exchange for wealth, and even spawning offspring a few times and guiding them to adulthood, was all satisfying for a long while, but eventually... He got bored.
And so, the Seeker wondered if the long sleep for the journey between stars was really necessary, and got to work seeing about making it not. He managed it eventually, and built a starship, and went exploring. Stars come in a beautiful variety of kinds, and the worlds around them do too, but very, very few bear any sign of life. They are mostly barren and empty.
...Oh, this one is emitting curious amounts of low-frequency light. Worth investigating. Pushing a starship faster than light requires a touch of magic (at least for now), which he provides.
In the outer solar system of a certain star, well above the plane of the ecliptic, a black sphere the size of a city block appears and has a look around with powerful telescopes.