Symbolism, Imagery, Allegory
In what universe does it seem like a good idea for an FBI agent to host dinner parties with known gangsters?
Even though "the FBI in no uncertain terms banned socializing with informants," dinner parties become a ritual for the corrupt Organized Crime Squad and their two favorite informants, Whitey Bulger and Steve Flemmi (2.9.49).
The group usually gathers at John Morris' home, though they sometimes drop by Whitey's instead. As you can imagine, Morris' wife Rebecca isn't too pleased to be cleaning up after murderers, and the tension between the married couple over this issue is a big contributor to the dissolution of their marriage.
And who can blame her?
These parties also illustrate the unsettling closeness that's developed among the fearsome foursome of Connolly, Bulger, Morris, and Flemmi. They're meeting in Morris' home after all; this relationship has transcended business and is now personal. Plus, it's at these meetings that things get truly dark.
Check it out:
Morris, his wine nearby but clearly sober, said, "You can do anything you want as long as you don't clip anyone." (2.13.43)
This is the moment that the book's writers dub a "black mass"—the moment Morris and Connolly transcend a grave moral boundary and become criminals themselves. The fact that it happens during a casual dinner party only makes it somehow darker.