If you want the "libertine" part, go to the source. Sade's work is the ultimate exploration of power without morality. While not "invisible," the characters create a hidden, secret society of depravity.
Many of these works were written during eras of strict censorship. They are often studied today for their cultural and transgressive value rather than just their plot. Digital Safety: El Libertino Invisible Pdf
If you have more context — such as the author’s name, year, or where you saw the title — I’d be glad to help identify it. Alternatively, if you meant a different title (e.g., El jugador invisible , El libertino by a specific author, or a known work like El mito del libertino ), let me know and I can produce a proper report on that. If you want the "libertine" part, go to the source
Technical papers on stimuli-responsive materials that use "invisible" inks for security purposes. Many of these works were written during eras