The designation was not a mistake, though the censors wished it were. Scrawled in faded blue pencil on the edge of the technical schematic, the index read: I--- Antonov An-990.

It sounds like a heartbeat.

It sounds like an engine, idling.

The “I” in its name was redacted from all official logs. The official story claimed the An-990 project was scrapped due to “metallurgical fatigue” in the wing spars. But the real reason was the flight of November 12th, 1988.

For seventeen seconds, the An-990 sang a note that did not exist in nature. It was the frequency of a womb. The frequency of a door closing. The frequency of the instant before a lightning strike.