This is a tale of swashbuckling adventure on the high seas of the 17th century. Captain William Kidd was not actually a pirate, but employed by King William III to track down pirates and requisition their treasure - the semi-legal role of the "privateer". As a counterpoint to his story, Zacks also tells the forgotten story of his great rival, Robert Culliford, an utterly ruthless buccaneer who flew a blood red flag which signified "no mercy" and whose surgeon was named Jon Death. Kidd's and Culliford's paths were to cross again and again during the course of their lives, but in a tale of double-crossing, betrayal and political scandal, the outcome was not as expected. One of these men would end up hanging on the gallows of the London dockside; the other would walk away with the treasure.