When Robin is struck down by polio at the age of 28, he is confined to a hospital bed and given only a few months to live. With the help of Diana's twin brothers (Tom Hollander) and the groundbreaking ideas of inventor Teddy Hall (Hugh Bonneville), Robin and Diana dare to escape the hospital ward to seek out a full and passionate life together - raising their young son, traveling and devoting their lives to helping other polio patients.

In Ancient Akkad, Mathayus grows up as the proud son of Ashur, a captain in the world-renowned military corps of Black Scorpions, first-rate bodyguards, most of which are sent to courts wide away. By objecting to young Mathayus joining the corps, Ashur incurs the undying enmity of ruthless generalissimo Sargon, gets killed and the orphaned knave is shipped off to a desolate training camp for six years by king Hammurabi's clemency. When he returns as a Black Scorpio, Sargon has bloodily seized...