Irish Whiskey by Andrew M. Greeley is the third book of the Nuala Anne McGrail mystery series set in late-20th-century Chicago. Dermot Michael Coyne and his bride-to-be Nuala are just a few weeks away from their wedding. They can't "coast" blissfully into the event, however.
On a visit to Dermot's grandparents' graves, Nuala is disturbed by Jimmy "Sweet Rolls" Sullivan's grave. She insists they must investigate why the 1920s bootlegger (rival of Al Capone) is not really buried there.
Nuala's jealous and manipulative brother Laurence wants to prevent their wedding. He tries to turn all her siblings against Nuala & Dermot's nuptials. Luckily Nuala's parents have met Dermot, when he visited Ireland and fell in love with Nuala (book 1 of the series). They know he's a good man.
If that is not enough to keep them busy, vindictive, twisted Dale Quade, Assistant US District Attorney, is out to get Dermot. She'll stop at nothing: breaks the law and legal ethics in the process. But never fear, Dermot's sister Cindy is a talented lawyer adept at courtroom battle.
Above all, enjoy the witty banter, portrayed as the Irish manner of speaking. For full enjoyment of the relationships and antics, read the series in order.