In the "De Insomniis - Plenilunio" collection the subjects hover in the void, at other times they sink into marine abysses, or emerge from a web of shapes and lines that dissolve into the abstract. Infinite perspectives of powerful architecture or very fragile structures, which can be moved by a gust of wind, are the background of an intense oneiric scheme. Petrelli depicts the infinite impotence of the human being in front of the occult, the "non-manifest". The artist acquires the gift of a prophetic power, an intuition coming from the fall of all mental schemes. A means of revealing to the common man something happening in one of the three times (present, past or future). Sometimes the subjects look pure and free, sometimes ugly and gloomy. In this naturalness, without aesthetic schemes, the true state of mind of that person, in that precise instant, is revealed.