2084: In a post-apocalyptic world controlled by UniCorp, where the memory of the "genetically inferior" has been chemically tampered with, Alowa escapes her captivity as a dispenser. She is sheltered in the reservation where dangers abound and her fears grow that she might be an "immigrant" - a bioengineered facsimile of a human being. She is told a boy called Solstice has her memories and she will have to enter History to find him. 1943: Max's family have been deported from England to Italy when Mussolini declares war on Great Britain. Max has Italian lessons with a Jewish woman and falls in love with her daughter. Then the Nazis arrive in the sleepy fishing village. 1890: Weayaya, living on the Standing Rock reservation, dances the ghost dance. Then Sitting Bull is killed and she and her young son are among the Lakota fleeing towards Wounded Knee. The Memory Tree: four interlocking narratives which forge a thrilling path through time and heritage.