The bratty lover
Although Berendt doesn't know what to think when he first arrives, he does notice that Jim Williams and his assistant Danny seem to have a unique, suggestive relationship. Before long, the reader knows the truth. Danny is rude to Jim because Danny is Jim's lover, and Danny is a bratty lover to Jim, because he enjoys that kind of attention. Beyond the dramatic irony, there is technical irony, because the love affair is devoid of affection or kindness.
The murdered lover
Perhaps a married person might suggest that this is not as ironic as it seems, but it is very ironic still. Romantic couples should not kill each other, obviously, but the irony of the situation is that people are very difficult to live with. Jim kills his lover Danny, because he is extremely unstable. Murder is ironic, of course, but it's even more ironic to betray a partner. Jim could have probably kicked Danny out, but he killed him instead.
Lady Chablis
A glaring irony is Lady Chablis. Her character is a riotous rejection of the typical Southern culture of Savannah, Georgia. She is a transgender person or a transvestite, it isn't clear which, and she is well connected. She helps the story along tremendously, and her identity is paradoxical. Her role in the story is delightfully ironic, because the folks who obey Southern social constructs are often evil, but Chablis is honest, forthright, and trustworthy.
The irony of gossip and truth
Although there is a narrative given that explains away all of the suspicion, Berendt is still suspicious, and for good reason. Through gossip, he learns truth about the situation that he would not have known otherwise. It is ironic that the truth is only available through the grapevine, because gossiping is typically frowned upon, but in this case, it is an essential part of justice.
Money and power
Although Jim is originally wealthy and powerful, he stays in jail a lot in this book, and he is limited. He is not able to solve his own problems anymore. Why? Because although his money gave him one kind of power, it didn't give him all the kinds of power. Without the power to control his temper, he fails. He commits murder in his rage, which shows that ironically, he has no power to control himself. Money and power are ironically reversed in the plot.
