Melanie Klein expanded our understanding of the Oedipus complex by developing the notion of the child’s internal world, inhabited by figures derived from early experiences, whose qualities and functions are influenced by projections and distortions. She showed how, in the child’s phantasy, these figures relate to one another in complex ways, and some of these relationships constitute early versions of the Oedipus complex (Klein, 1928, 1932; also chapter one in this volume). Part of the power of her clinical theories derives from the way she was able to use her understanding of the nature and relationships of these internal figures to recognize what was being experienced and enacted by the child, in the clinical situation, as it was made manifest in the transference.