Professor John Guy examines the original 16th century documents to investigate the case of Queen Elizabeth I's doctor, Rodrigo Lopez. Dr Rodrigo Lopez was accused of plotting to poison the queen and he was subsequently charged and sentenced to death. The queen had doubts as to Lopez's guilt, but was she wrong to trust a man who was a known spy and who communicated with the courts of Spain and Portugal? David Katz from the University of Tel Aviv is the only historian who thinks Lopez was guilty, and using his extensive research he tells us why. The documents lead to a complex web of spies and betrayed loyalties in the Elizabethan court.