Both the title of this book (A Fork in the Road) and the subtitle (Questions on Doctrine: The Historic Adventist Divide of 1957) suggest the idea of two—where once was one.
So too does the author's metaphor—which he used to great effect in his original presentation of this material at the Questions on Doctrine 50th Anniversary Conference at Andrews University in October of 2007—of two clashing tectonic plates. In other places, he described what happened following the publication of QOD as an earthquake.
Whatever the metaphor employed to describe the legacy of Questions on Doctrine, its impact on Seventh-day Adventist theology has been profound. So much so, that perhaps it's only understandable that no one metaphor can capture the extent to which this one book would affect Adventist thinking even a half century after its publication.