In the "Vault", a world torn apart by the "Great Silence", the remnants of humanity live on an empty island suspended by ancient technology, with a roiling poisonous miasma below. Kyle, a low-level scavenger, is forced to embark on a desperate journey to save his sister who is suffering from the mysterious "ether decay disease" and whose body is gradually crystallizing. His only hope is the legendary "Heart of Origin" located in the capital of the ruling class.
The power of "Resonance Attunement" that he was born with and considered taboo is not only the only key to saving his sister, but also makes him the prey of two major forces: the "Sons of Silence", a fanatical sect that regards him as a heretic, and the "United Council", an authoritarian oligarch eager to control his power.
From the crumbling ruins of Rusty Port, to the crisis-ridden sky routes, to the glorious Apex City. Kyle will form an alliance with the reclusive mechanical master and the free-spirited ace pilot, and step by step uncover the suffocating truth behind the "Great Silence" - this world is not a home, but a cage.
When the end comes again, destruction and protection are just a matter of thoughts. Kyle must make a choice: become the lock that strengthens the cage, or sound the final elegy to the silent world?
