The high stone walls of Barbal encircle a deep rift. At the heart of the city the Lord Alchemist, Mardak the Dark, reigns supreme. His pursuit of power has led the tyrannical ruler to treacherous deeds: seizing the opposing alchemist, Ogog, and holding him hostage in the Ziggurat. However, help is at hand in the shape of a young boy called Silas. Under the guidance of his charismatic mentor, Sultan Ash, Silas sets off for Barbal to free Ogog, armed with nothing more than sheer determination - and a pure white pebble in his pocket. Unbeknown to Silas, the pebble is a Turnstone, a talisman bestowed with magical powers. In Barbal, Mardak's wild obsession has culminated in the construction of the Entropoth, a deadly time machine powered by human souls displaying events happening in the past and future. Mardak may know Silas is on his way - but will he be a match for the Turnstone?