When the Void Stares Back
Before Planet X first returned to the Solar System, there were signs of his lurking about.
Swaths of displaced asteroids that were noticed by the dwarf planets in the Kuiper Belt.
Gravitational anomalies felt by the Uranian and Neptunian systems.
Random dark patches in the sky, as if something was blocking out the stars.
And Ariel, Uranus’ adventurous, curious moon, swore she could see a pair of eyes staring back at her when she concentrated her attention into the darkness beyond home.
This is, obviously, pre-"Planet X Arc." I imagine the tiny outer moons of the Solar System were aware of something hanging around out there in the darkness before anyone else knew of X's presence.