 Yes, and we've also been sampling individuals that spans at least 120 years, and what we find is that it's only towards the end of this time period that plague becomes really prevalent. So what we believe happened is that maybe the plague was present early on, but then at some point it gets, well, very abundant and basically kills the population. How much information can you get about the plague bacteria itself? I mean, is this related to the famous Black Death of the Middle Ages?