In the year 2112 Dr. Bernard Wilkins invented time travel. The following year the Trans Star Institute was built and Dr. Wilkins wrote the Prime Directive, "Do nothing to alter history." Over the next twenty years field agents risked their lives as they carefully retrieved lost or destroyed works of art from history. During those years the Prime Directive was never violated. But two new filed agents, in search of the Holy Grail, will stretch the very fabric of time to the breaking point. Now a young agent's life hangs in the balance, and Dr. Wilkins will be faced with the decision whether to save a life or violate the Prime Directive.