During a highly divisive and unstable period of British history, father-son duo William and Robert Cecil helped foster one of the world's first secret services. Charged with the protection of Queen Elizabeth I, this pioneering network of spies fought off assassination, treason and terror for over 40 years. "Elizabeth I's Secret Agents" delves into the most important events of the Elizabethan period, from the execution of Mary Queen of Scots to the death of Queen Elizabeth I and the Gunpowder Plot.