[Tellus]

One turn, in a sp game I'm playing as Pythia, I received this message: "Yna, the Hidden One has broken free."

Who is Yna, and what does this mean? This is long past the time of the imprisoned pretender gods. There is no Yna unit anywhere in my territory that I could find, and I'm pretty sure it's nothing I've done. Is this a R'lyeh summon powerful enough to need a message for other players?

I'm at a loss.