On a particularly normal day on the planet Earth in an average sort of month at a perfectly meaningless hour, a message arrived.
It came on wavelengths of light and radio and other things; it was registered in telescopes and satellite transmission; it was about nineteen seconds long and it was very complicated and then it stopped.
It also had arrived from Tau Ceti. Probably.
***
There were Concerns.
Some were excited about the message, believing it was a sign that not only life existed elsewhere, but it wanted to make friends. Some were skeptical, believing it was some sort of meaningless nonsense. Some were paranoid and believed it had been done by other humans as part of a nefarious plot that explained the sixteen other nefarious plots they already believed other humans were masterminding. Some were a little TOO excited, believing it was a sign from someone to do something. And most of them were a few of the above mushed together in one way or another.
This led to arguments which led to escalation which led to death which led to more arguments but louder and hoarser. Explosives became involved.
Meanwhile, some small groups of people, in varying degrees of secrecy and isolation, worked on the message. Was it a warning? Was it a threat? Was it a welcome? Was it a secret? Was it a gift? Was it a puzzle? Was it abstract, obtuse, and convoluted or simple, straightforward, and direct? Computers were designed and applied; codebreakers and mathematicians and linguistics experts were grouped and employed; occasionally someone was killed with high-speed explosives by someone else, and the world, with increasing erraticism, spun on.
Then the second message arrived. It was half as long as the first, and had half as many characters, and halfway through receiving it someone launched a nuclear missile, which caused other things to happen.
***
While the first sets of missiles were in the air, one of the earlier teams managed to crack the first, more structured message. It was a plea for assistance from someone, anyone, since the sender’s society had torn itself to shreds from pre-existing internal divisions while trying to decipher an inexplicable message they’d received from space, and they were placing themselves at the mercy of any potential recipients, whom they hoped would be wise and benevolent.
The second message was a useless assemblage of symbols, such as might be created by something or someone falling over on top of an input device.
***
The code team decided not to bother retranslating the message into earthly languages before rebroadcasting it. It would’ve taken time they didn’t have, and after all, this one had already proven itself to be decipherable at least once.