In «Horizonte» (4, 1999) Georg Maag resumed the plot of the novel La malattia del commissario, which appeared in 1994 (Sellerio): «Inspector Leandri, whose metaphorical illness consists in being unable to explain the existence or the mere possibility of evil in the world, has to investigate the murder ― or was it suicide? ― of his former schoolmate Enza Gorla, and his meetings with the suspects finally turn into a disconcerting confrontation with his own generation, a sort of "descent into hell." They are all old school-mates and they all participated in the student protests of the sixties. Leandri's investigation fails to lead to the discovery of the murderer, but makes painfully evident what became of his generation after the end of the student movement.»
In a similar vein, although paying greater attention to the social conditions of present-day Italy, Titus Heydenreich (in Carlo Levi, Il tempo e la durata, Rome 1996), has this to say: «La malattia del commissario: perhaps a novel of investigation, but the author's intentions go much further: the action should be read as an example of the vanitas vanitatum of the battle of a lone figure against evil. Leandri, the inspector, foresees that he'll fail to solve the enigma of the nth murder in the chaotic capital of Lombardy. The "illness" consists of the fact that the main character cannot or will not resign himself to the evil that has massively invaded the life of the entire nation. It is symptomatic of our case that Leandri's profounder, more pessimistic reflections unfold in the course of a journey on the North Italian railways. As can be seen, it would be unjust to speak of a vituperatio patriae. It is more of a lament that calls to mind Leopardi 's no less disconsolate verses on Italy after the humiliations of the Congress of Vienna.»
In an interview with «La Notte» De Marchi confessed that he had originally intended to write a novel about a generation but that then the problem of evil and the meaning of human behaviour moved decisively into the foreground: «In my conception of the story I felt the desire to write a novel against rather than about my generation. But proceeding with the first draft I realised how vague and deceptive the concept of "generation" was (…) A detective, like a doctor, and also like a writer, represents order: to combat something he must first try to find its cause. The same is true of the doctor in is efforts to cure his patient. On a lower level the writer too fights against the disorder of language. Unfortunately, the real world only seems to tolerate such order in exceptional cases. From the minor theft to the enormity of war, from the common cold to the epidemic, from childish stammer to the confused babble of human voices - the ease and reassurance of normality is in fact continually compromised by the presence of evil. To become aware of this is to succumb to the same illness as Inspector Leandri.»
More and more clearly therefore, the centre of the author's themes and interests would seem to be occupied by evil or, if you prefer, disorder.
The fact that the doctor appears among the examples quoted in the interview, could be read as foreshadowing the next novel Una crociera. In the simplicity and directness of his structure, formed by meetings between the main character and various persons in turn, La malattia del commissario offers the reader a great variety of characters, situations, linguistic and stylistic levels, which all merge in the inspector's continuous and almost obsessive indirect free speech. Even when the harshness of the situation and the language might suggest a realistic or even naturalistic intention, the presence of the main character's anxious eye once more shows that all of De Marchi's narration is filtered through a figure, at once crippling and - in a literary sense - vital. And through this filter the reader gets to know the dark sides of present-day society - political extremism and utopia, drugs, sex, cynical social ambition, the ebb of ideologies and the impotence of rancor.
Among the many figures in this novel there is the character of the light-headed architect Leone Prizzi, who got rich by planning horrible buildings for the nouveaux riches of Lombardy, and whom the text endows with an impudent glib tongue. The author himself has stated that here «for the first time [he] succeeded in writing fluent direct speech, a curious mixture of cultivated and spoken language. Leone Prizzi served as the model for Carlo Marozzi» - the main character of Il talento.