This is the story of the Church of Aghia Sofia in Constantinople, of its long and illustrious history and of the quest by a young seminarian to restore it to some of its earlier greatness. Built in 537 AD by Byzantine Emperor Justinian, Aghia Sofia served as the Mother Church of the Byzantine Empire and of the Orthodox East for nearly one thousand years. In 1453, on the conquest of Constantinople by the Ottomans it was converted into a Mosque. Since 1932 it has been serving as a museum and a major tourist attraction of the city. The story begins when Mark Jason, a seminarian and convert to Orthodoxy, travels to Mount Athos in search of some materials for use in his School thesis. While at Athos and later during a visit to Constantinople he hears references to the JUSTINIAN DIARIES, a unique collection of chronicles on Aghia Sofia dating back to the Byzantine era. The collection is rumored to be at the Monastery of Meghisti Lavra on Mount Athos but its precise location there is unknown. Troubled by the use of Aghia Sofia as a museum, Mark begins an active search for the JUSTINIAN DIARIES. Publicizing their contents, he reasons, will remind the world of Aghia Sofia's celebrated history and help free it from its present role. His search encounters numerous obstacles, including hostility on the part of the authorities at Mount Athos who insist that the JUSTINIAN DIARIES are a myth...