Do we truly know who Shakespeare was? Could the plays and sonnets have been written by more than one person? This historical mystery revolves around two possible candidates, Mary Sidney Herbert and her famous brother, Sir Philip Sidney, poet and courtier, in the court of Elizabeth I. Born in the same era as William Shakespeare, their lives were as real as his, and the three may even have met. Their story interweaves with the modern tale of Sarah and Janek, as they explore modern day London and the British countryside, searching for clues to prove Mary and Philip Sidney's contributions to the works of Shakespeare, a thesis one of them very much believes in. They are not alone. Two unidentified "watchers" are following them, hoping to discourage their search or to steal whatever information they find. After many dangerous adventures, their quest leads them to Carisbrooke Castle on the Isle of Wight, where another mystery awaits them.