them. For a first attempt, it was the most basic of communications: the first ten prime numbers, represented as a series of blips. Then I waited for a response. I had listed a number of possibilities while waiting for them to arrive. It might be the next ten primes, or it might be my message relayed back to me in reverse, or it might be another mathematical series. Or it might be a blast of cosmic rays. I was not expecting an audio message, in Mandarin.