Starfall Protocol

Communications Officer Yael Orin had been monitoring the deep-space relay array for six years, and in that time she had logged eleven thousand, two hundred and forty-three transmissions. She knew the frequency signatures of the survey drones, the research stations, the long-haul freighters moving through the outer belt. She knew the particular signature of interference from the gas giant's magnetosphere, which occurred in a predictable cycle and which junior officers always flagged as anomalous until they had been on the relay long enough to recognize it. She knew, in the way that genuine expertise always reveals itself, the difference between a signal and noise.

The transmission that arrived at 03:17 station time on the forty-second day of her current rotation was a signal. There was no question about that. It was formatted correctly, it carried a valid legacy header, it used the old encoding standard that had been deprecated twenty years ago but which all relay stations were still required to support for legacy compatibility. It was, in every measurable sense, a routine communication from a registered probe.

The problem was that the probe's registration number belonged to the Isadora, a deep-space survey drone declared lost with all data in 2381 — forty-one years ago, when Yael had been three years old. The Isadora had been on a mission to the far side of the Kuiperanalogue, had missed three consecutive check-ins, and had been written off as a casualty of the debris field it had been sent to map. A memorial notation had been added to its registry. Its mission parameters had been archived. There had been no signal.

Until now. Yael ran the verification sequence four times. She woke her supervisor, who ran it twice more and then went very quiet for a long moment before saying, in a voice carefully stripped of inflection, that she should not log this through the standard channels. She asked what channels she should use instead. He told her he would find out. He left the communications bay without his coffee and did not return.