In 1965, neuroscientist Margot Sharpe meets the attractive, charismatic Elihu Hoopes - the 'man without a shadow' - whose devastated memory, unable to store new experiences or to retrieve the old, makes him the most famous and most studied amnesiac in history. Over the course of the next 30 years, Margot herself becomes famous for her experiments with E.H. - and inadvertently falls in love with him, despite the ethical ambiguity of their affair, and even though he remains forever elusive and mysterious to her. As the story unfolds, it tracks the intimate, illicit relationship between Margot and Eli, as scientist and subject embark upon an exploration of the labyrinthine mysteries of the human brain. Where does 'memory' reside? Where is 'love'? And is it possible to love an individual who cannot love you - who cannot even 'remember' you from one meeting to the next?