This article provides an analytical reading of a poem by José Gorostiza on which writers and academics in Mexico have spoken and written a lot and with great admiration. It is a poem that Octavio Paz identified as a ‘rock glass watch’ in order to synthesise its content and apprehend its constitution. This is perhaps the most important work of the so-called Contemporary group, which, in its aesthetics and public attitudes, opposed the degradation and abuse of national affairs in the state culture of the post-revolutionary regime in our country, and in doing so opened the door for intellectuals to be independent from government power.