After a promising debut with Belle, Amma Assante is back with another little-told piece of black history. The real-life story of Seretse Khama, a prince and ruler of Botswana, and his white English wife Ruth Williams, it features the excellent David Oyelowo and Rosamund Pike and makes the most of its glorious African location. Unfortunately, like Belle, it suffers a bit from under-done pacing and storytelling.