The story takes place over the course of a week in which Mary, the mother of Jesus, shows up and asks to stay with the protagonist as respite from all the demands on her time and energy. Intercut with this story is a history of a number of visitations Mary has made over the milennia -- at Guadaloupe, Lourdes, Fatima, etc. - related by the protagonist from her research after Mary left and by Mary describing things from her point of view. What I appreciated most was the interior monologue of the protagonist about the nature of faith and doubt, and what 'history' really is - and is not. Touching, funny, worth re-skimming at some point. Side note - I was also surprised to realize that I'd remembered more than I'd thought from my Catholic school religion classes about a number of the appearances of Mary.