Herodotus claims that in 525 BC, Persian king Cambyses II sent 50,000 soldiers across the Egyptian desert to destroy the oracle at the Temple of Amon, and that the entire force vanished in a sandstorm and was never seen again. This film tracks the search for physical proof, starting with desert explorer Laszlo Almasy, who claimed in the 1930s to have found traces of the army before dying without recording their location. In 1996 a geologist working in the desert turned up bone fragments and ancient arrowheads, only for Egyptian authorities to close off the site before the find could be examined further. A new team of archaeologists and geologists returns to that ground, testing whether an army could realistically have crossed the terrain at all: the film works through the logistics, an estimated 3,000 tons of food, water, and supplies, and the total absence of reliable maps for the route Herodotus describes. The result sits between forensic reconstruction and open case, weighing a specific ancient claim against what the desert itself will allow.