The Day of Convergence is approaching, and everyone in the solar system must prepare. Lumina has gathered as many Cosmic Guardians as she can to stem the tide against the deadly black hole Guardians looming outside the galaxy's borders. Should they breach her line, they may travel to Geon and slaughter the humans living there. Worse, they may even break through to attack the humans on Geon. Or worse, destroy Helio and the sun while he sleeps. One lesser Moon Guardian, Neera, might have concocted a plan to help boost their chances, but can she convince Lumina to let her try?
On Geon, the Moon Princess and Sun Prince prepare the citizens of Geon for their part in the battle. The entire Night Guard trains nightly for combat with supernatural Cosmic Guardians while the rest of the populace get ready to evacuate to specially prepared bunkers. Reilly and his friend, Sage, are doing their best to put a good face on it all, but a mysterious Silence plagues their thoughts. What is this Silence, and what do the two boys have to do with the war brewing in the heavens?