Thousands of years ago in the Zagros Mountains at the northern edge of the Fertile Crescent, a small village is raided by slavers. The only one to escape is a small boy who flees north. He is overtaken by lions. A passing aircraft of time explorers tries to rescue him but arrive too late to save him. Their plea to go back to save him is rejected by the Agency that controls the time portal. The small band of explorers, Sam Habib, son of a Lebanese merchant, Joanna Dzingira survival of the Medieval Black Death, and Sean Mulcahy, from a family wiped out by the Irish Potato Famine are left angry and frustrated.The Agency sees Time Travel as a highway linking the past through the present to the future; a highway that needs to be watched and guarded. Yet to many of the agents time is more than a mere road. It is a crossing leading off to an infinite number of worlds. For them patrolling time would be like trying to play chess with an opponent who knows every possible move you might try to take. If time travel can exist then it must already exist for we who live in the past are bound to those who will dwell in the future, who if possessing time travel, will jealously guard its origins keeping it away from those too immature to understand it or to control it.In purchasing the right to the portal the European Union sees it as a means of protecting itself from its rivals in Asia and the Americas. On one of the last of its overseas possessions, Pitcairn Island, it builds a portal. There in the remote waters of the south Pacific protected by a naval blockade it hopes to control time itself. The Agency created to build and manage the portal finds itself in the uncomfortable position of being caught between those anxious to explore the possibilities of time travel and those afraid of its possible threat to the world's political and economic stability.Agents are of two origins, Islanders, orphans rescued from the past, trained to serve the agency and mainlanders, born in the modern world. Apart from these two groups one other, its numbers shrinking with every year, lives on Pitcairn, some of the original islanders. Soon there is only one left, Jane Christian living on her farm outside of the control of the agency. Keeping away from the agency Jane lives out her days, a woman who has never left the island. Her one companion is her adopted daughter Joanna Dzingira. The agency aware that is failing in its attempt to control time is also losing agents who one by one are disappearing into the past. The loss of Sean Mulcahy, Joanna's lover, causes the Agency to offer Joanna a deal, to let her save the child they once rejected. In return she will travel into the past to find the missing agents. The agency gambles that her ties to both Jane and the child will keep her from defecting.Joanna agrees to search for the missing agents.