The Opus Gemini and the Antikythera Mechanism

In 161 A.D., only one such device is still known to a few insiders of the Roman Empire: the Opus Gemini, last surviving sibling of the Antikythera Mechanism that has been lost in the sea long ago, forged by the astronomer Geminus on the island of Rhodus. The Corpus Sacrum trilogy (Societätsverlag Frankfurt, 2006) told how Geminus' mechanism came to its current location twenty years before this story begins. Knowledge of Corpus Sacrum is not required to enjoy the Opus Gemini trilogy.

According to Corpus Sacrum, Princess Iulia Balbilla, interpreter of the Codebook of the Cosmos, was exiled by the Roman emperor Antoninus Pius in about 140 A.D. She has been biding her time since in the border city of Samosata on the river Euphrates where once stood the throne of her royal ancestors, the last kings of Commagene. Now Antoninus Pius is dead and Roma has new lords: Marcus Aurelius, also called the Philosopher on the Throne, and his co-regent, Lucius Verus. For the first time, the Imperium is ruled by two emperors together. And at once they have to face a mighty foe: Vologaeses IV, king of the realm of Parthia, has taken the opportunity to invade the Eastern provinces. As Princess Balbilla escapes from the sack of her place of exile, she plots her return to the summit of power - and for this aim she needs the Opus Gemini.