The story of Mattia, a talented young doctor, takes place in Venice, he has been summoned to heal an old writer, Riccardo, by Valentina, the writer's nephew.
Mattia, before reaching Riccardo's dwelling, passes by Poveglia, an ancient island in the Venetian Lagoon where several events related to the history and culture of the "Serenissima" took place. Once a quarantine and then a mental hospital, the island is deeply engrained with dark legends about plague and madness. There, the young doctor faces, for the first time, some oddities which will pursue him through the whole journey; as a mysterious figure he will spot whistling a sinister melody along the hospital's ruins.
Once in Riccardo’s dwelling, his visions will worsen. Venice and Poveglia's past will combine with the present as will the old writer and the doctor. As Mattia has no choice but to trust the otherworldly Valentina, he will find himself on the edge of sanity, with nothing certain.
Mattia will witness this blurring of past and present, reality and fantasy, fighting for his life all along.
Valentina - a malicious and controversial character, over-protective and haunted by the vision of the plague doctor - will accompany Mattia along all this confused dreamlike experience.
The Plague Doctor, with its classic black mantle and gloomy white mask, will haunt Mattia's nightmare.
As the time goes by, realty will be more and more fragile, between evocative images and echoes of past events.