S1, E4: From reconstructing an ancient Neanderthal cave, to retracing an ancient woman's footprints, to decoding the Herculaneum scrolls, scientists decipher the past by examining traces of history that have disappeared.

S1, E4: From reconstructing an ancient Neanderthal cave, to retracing an ancient woman's footprints, to decoding the Herculaneum scrolls, scientists decipher the past by examining traces of history that have disappeared.