In this article, I examine the work of the negative, in particular denial, through the case of a sick child and his family, and its transformations. A child's serious illness mobilizes the family group in particular to deny, in a collusive manner, breakdown and death anxieties. I hypothesize that Emile's serious illness shifted the family alliance from a narcissistic contract to a negative pact. However, according to several authors, the negative has a double significance and can be structuring. I will show how therapy and playing with this child encouraged the emergence of greater symbolization and the elaboration of the Oedipus complex, or how to move from a devastating, disorganising negative, a pure product of the death drive, to a structuring negative, where life drives and death drives become entangled. The analyst's investment in the child's psychic life allows the objectalising function to unfold, which, as this therapy shows, involves taking the sexual function into account. Narcissistic issues are also dealt with, in an intricate way.