"Somehow I get the feeling we'd already know if that were the case, but perhaps not. This is well out of my realm of expertise at this point."

He shook his head, "Honestly, I'd be more concerned that we're going to end up facing them than the possibility that we already have." A little shrug, "After all, historically, or at least legendarily, this sort of thing rarely goes well for the ones living through it. Though we can't have met that many times, given even a below-average life-span. There are only so many centuries between then and now."