This thesis makes a comparison between the internal dialogue of the Empress Carlota of Mexico in Noticias del Imperio (1987), by Fernando del Paso, and the internal dialogue developed in the original written letters by Carlota during her insanity in 1869. These letters were published in the book Una emperatriz en la noche (2010) by Laurence van Ypersele. Del Paso uses the New Historical Novel genre to write about the French Invasion in Mexico and to bring back to life Carlota, Maximilian, and Benito Juarez amongst others. In the case of Carlota, del Paso uses fiction to recreate the thoughts of a clinically-declared insane woman. The author of Noticias del Imperio can only imagine how the mind of an insane person works based on historical texts describing the behavior of the Empress during her sick years. Overall, when comparing both Carlotas, del Paso captures with great magistry the way of thinking of a mentally ill person, and there are a lot of similarities between both worlds. However, as time goes on and the Empress continues writing her letters, her insanity worsens and one can appreciate a reality that del Paso could have never imagined to recreate in his novel. The written correspondence during Carlota’s insanity becomes more confusing and one can notice a complete transformation of her world, which is perfectly logical to her. In these letters it can be appreciated that the reality of insanity, surpasses the fiction written by del Paso.