Watchtower is a short story about first contact. The main character, an explorer in an ever-shrinking world, is contacted by a Muskian character about a new 1G space drive he’s developed. The moment it was fired, a nearby asteroid split in two. They visit, to find it is a watchtower, left by an alien species who knows how long ago. It explores the fact that “space is vast and time is deep”, and that all species who achieve space travel are likely doomed to be the only ones around in their little bubble of spacetime.
Somewhat implausible, but nicely written.
10k words.