What was the issue of The Villa of Mysteries?

I assume you mean the "Villa of the Mysteries," the ruins
of a Roman villa near Pompeii dating to the 79 A.D. eruption of Vesuvius which destroyed
the city. At the time of the eruption, the villa was buried under volcanic ash, but the
frescoes painted on the wall were largely
unharmed.

Tremendous historical debate has ensued about the
meaning of the frescoes. They purport to be a religious rite, but its exact nature is
unknown. Among the various interpretations are that the frescoes depict a young woman
participating in a marriage rite; and another that it depicts a young woman about to
undergo initiation into a secret group known as the Cult of Dionysus, the god of Wine.
It is known that the cult required certain rites of its initiates, and there is
substantial speculation that this is represented in the frescoes. Sadly there is no
definitive answer and probably never will be.