Mystery markings

Two kids find them selves all alone in there small little town one day. But thats not all, they each have strange markings all over there bodies. They seem to look like markings from old runes but they don't know what runes there from. They then decided that there goal was to find out what else has changed and where the hell the markings came from.

NOTICE---- there will be some romance and a few parts that do get a little dirty, along with a few things that might seem a little crazy, but that's just how I write/imagine things. And they are older than 21, so you can just say they are 21 if you want