Sometimes, a writer inadvertently creates an Alternate History, which causes problems when referencing later events. The reason? Real time has simply progressed beyond the fictional events. Adventure thrillers are especially vulnerable to this, as they are often written Twenty Minutes Into the Future. Sometimes, the writer will refer to later events such as 9-11, In Spite of a Nail. In other cases, what was a series of adventure novels experiences a Genre Shift and becomes some kind of science-fiction or true Alternate History. Science-fiction examples: