I'm really fascinated by how the mob ethos permeates places like Las Vegas and Chicago. I have the book set in Las Vegas and Chicago for pretty specific reasons, some of which are that in both cases the mob history has become a tourist attraction - I'm actually doing a book signing in Las Vegas at The Mob Museum, which I am positively giddy about! - and I find that especially unusual. If you don't call these people "the Mafia" they're just a band of psychopaths killing people for profoundly dumb reasons.