You're dying to know, aren't you?
You've been there-slash-know exactly how this goes down: Girl meets guy, guy asks girl on first date, they have a bomb ass time. Guy asks girl on second date, makeout sessions ensue. Guy asks girl on third date, which also goes swimmingly, and then girl never hears from him again. He might have died for all she knows. This leaves girl bummed/hurt/confused/and repeatedly asking her friends "Why would he do that? It's so unlike him!"
Now's the time to remind yourself that you didn't invest that much time into this relationship, and that this scenario unfortunately comes with the territory of dating. But that doesn't make it feel any less crappy after someone disappears after the first few dates.