Shortly before the Norman invasion, Alefthryth and Hereweald's lives end, and begin again. Cursed/blessed to live on, they step through time in a manner similar to the children in E Nesbit's The House of Arden - a kind of possession/symbiosis of existing people - but Aelfthryth and Hereweald have no control over where they go or who they become, and remember their former selves only after meeting, inevitably moving on when they reach their former ages (14 and 16).The poignancy of their repeated meetings and losses threads through a tour of the centuries, which is one of my favourite ways of learning about the past, taking a person from one time and having them become our lens to another. What gives the story an extra, bone-chilling edge is the where and when this story is told: an Alefthryth living in Australia in modern times has been kidnapped and locked in the dark with a fellow student, Saranna. Like a Sheherazade she is telling a tale to keep both their spirits alive. This device completely caught me up, and it's a story well recommended, especially for fans of E Nesbit.