The Eberswalde Enigma is an over-arching storyline that parallels Death in Podville. It is classed an unfiction work. If you haven't come across this term before it basically informs the person engaging the story that it is a complete work of fiction but the way it is told, it is treated as if it is real
There is an element of ARG in the story as well. Alternative Reality Game. This means there is some element of interaction or problem solving. But this is not a full blown ARG like some out there.
