As terrorism sweeps the globe, religious differences seem impossible to reconcile. Spiritual leaders of the Islamic and Christian worlds are turning to time-altering water clocks to restore the peace between faiths that once existed in medieval Spain. Among them are the Tejedors-a progressive Muslim family from Andalusia who believe the solution is to hasten the flow of time towards Islam's prophesied Last Day-and the Order of the Libraries-a rogue band of Christian nuns who slow down time for their salvation. While both faiths are intent on defeating terrorism, their time-altering tactics fundamentally clash, drawing the attention of a spiritually advanced First Nations tribe in North America who believe they are the guardians of time. The Tejedors' only hope to turn the hands of time in their favor is to find Tariq Kamal-a Pakistani-American linguist born to create the ultimate message of reconciliation-and to locate the Clepsydra-a 1000-year-old technology capable of broadcasting Tariq's message across space and time. Finding the Clepsydra, however, will require a revelatory journey into Spain's mystical past.