-¡Estafen! is a work with a judicial and prison theme, and at the same time a typical character novel. A swindler is caught. The arrest, the taking of statements and his dialogues with the judge give rise to a sharp critique of justice. The behind-the-scenes of prison life and his atypical and seductive behavior during the trial, as well as the logic of his thinking, make the Swindler an endearing character. The ending of the novel is narratively exemplary. Juan Filloy introduces in –¡Estafen! constant annotations and the technique of the flow of consciousness, resources that define a style that he will not abandon throughout his work.