The Castle, described as Hearst's version of the infamous Skull & Bones, had apparently been operating in secret for decades: a network of powerful men (and men only), made more powerful by their alliances and held captive by their secrets.
After a little undercover work by the long-suffering Wallace, a little theft, a little impossible hacking by the ever-impressive Mac and a side dish of destruction of evidence from dear old dad, Veronica unearthed those secrets and a comprehensive list of the Castle's membership.
But then what?
The information in Veronica's hands could have destroyed the organization; it could also have ended in criminal charges for more than one member we know about (and presumably many others we don't). So, what happened? Did Nish sue? Did Veronica share the information with authorities? Or did the whole secret society get swept back under the rug as the Mars family attempted to recover from the fallout of Keith's cover-up of Veronica's B & E?