The story of Carthaginian general Hannibal crossing the Alps with an army of 40,000 men, 9000 cavalry and 37 elephants is one of history's greatest legends. But the details of the journey - what route he took and how he and his entourage managed to conquer the treacherous mountain terrain - were a mystery, until now. For the first time, an international team of scientists is searching for clues hidden deep beneath the Alps' rocky soil, and their extraordinary discoveries are shedding new light on Hannibal's almost-impossible journey. The scientists are joined by paleobiologist Dr Tori Herridge and historian Dr Eve MacDonald, who follow in Hannibal's footsteps to experience what it must have been like as this ancient army battled raging rivers, hostile tribes and mighty mountains.