Strange symbols have started appearing all across Equestria that nopony can read, except Discord. As he comes to grips with what this message means, he is determined that nopony find out its secret. If they do, absolutely everypony in Equestria will die.
This story is a cosmological crossover with The Three Body Problem trilogy by Cixin Liu, and thus contains spoilers for that universe. But can be read without prior knowledge of that story.