The Seventh Observation Station had seven members. The six who could fight are all dead. The only one who survived was the most useless of them all.
Wen Sheng's resonance ability is called "Echo Archive." He cannot fight or defend himself. All he can do is store vanishing sounds in a case.
On the night the station fell, he sealed the last echoes of all six people inside the Frequency Reliquary: the captain's "Count to ten," the message the sniper never got to deliver, the joke that never made anyone laugh, the nineteen-year-old girl's "Record me, record me"...
These sounds refuse to disappear. The Eclipsestar Syndicate wants them, the Tideletter Society wants to destroy them, and he only wants to let them die in peace.
But he discovers that each use makes a sound grow fainter, and each memory he forgets leaves another part of himself hollow.
At the edge of the apocalypse, a post office opens to preserve the last sounds of the dead for those who need them.
"I can't fight, but I can remember."
