This case study addresses the question of families, both referential and literary, in the 2017 mystery novel «Qui a Tué Heidi?» (“Who Killed Heidi?”), by Swiss writer Marc Voltenauer. It sets out with the assumption that the family, despite the changes undergone, is still perceived as “the uncanny” and fascinates French-speaking authors, including those whose main stake is not its depiction. According to the initial hypothesis, Marc Voltenauer puts family matters at the service of his literary project. Several family stories are woven into the police investigation, which is typical for mystery novels and forms the core of the narrative canvas. These literary families, laden with secrets, dysfunctional and potentially pathogenic, are depicted in a hyperbolic way. Is this just a consequence of genre norms (the detective novel is based on a set of stereotypes) or does the author paint a troubling picture of the contemporary family and its metamorphoses? This is one of the questions the study attempts to answer.