They just silently disappear, and the result is chaos. Now imagine, instead, that the departure was far more catastrophic. Imagine that it was accompanied by waves of plagues, the destruction of the military, and the death of hundreds of thousands of men, women, and children. Then imagine all of this happening without leaving a trace. This is the Exodus, an epic of a subserviant people who constituted, if the Bible is to be taken at its word, roughly the same percentage of the Egyptian population as do today's Mexicans with respect to the population of California. Sometimes, the absence of evidence is evidence of absence.