Based on the clinical history of a girl with her mother and what appears to be a fraternal rivalry, the article shows the continuum between the envy of the early stages of life, envy in the Kleinian sense, and other forms of envy such as the desire to know. The relations between envy, mastery and the desire to know are explored. This transformation will be observed over two generations, beginning with the mother’s narcissistic pathology-envy of her daughter’s desire to know. The clinical manifestations of envy will be described, along with its consequences on the mind of the child who is envied or objects that are envied. The effects of projective identification revealing a pathology of introjection in the child will be observed. The forms of envy in the clinical experience of the transference and its effects in the countertransference will be described. The pair envious/envied will be explored as a figure of the double with its associated movements of uncanniness. The appearance of a somatic illness will raise the question of the economy of envy.