The historical documentary series continues with this fascinating investigation into the origins of the world-famous crystal skulls. Since the 19th century, a number of lifelike quartz skulls have been discovered and displayed in museums. These relics, allegedly dating from Aztec and Mayan civilisations, are believed to have psychic powers. Now, for the first time ever, scientists are given access to the most famous skull of all, the so-called ‘Skull of Doom'.