Edwin Kranz is a wealthy, difficult, eighty year old man who thrives on being annoyed. After recovering from a minor stroke, he realizes he isn't getting any younger and devises a plan to retain his independence and be looked after at the same time.
Edwin's only child, Ellie Mintzer, is a disgruntled nurse in her fifties who always craved his attention. She only knows him from weekend visits and short vacations during her childhood, but it's been a few years since she's seen him. Out of the blue, he's willing to give her the opportunity she's always wanted: A week alone in his old hometown to get to know each other better. She's hoping to find out how he grew up, what makes him tick, and how he came to be a curmudgeon. What she doesn't know is that he has ulterior motives in store.
There's an old, abandoned retreat in Edwin's hometown of Fallon, TX that was once a getaway for ill-repute. It sits on the edge of the lake outside of town and had been scarcely maintained over the years. Its short history is full of memories and scandals that are still fresh in the minds of townspeople. Its mere existence still sticks in the craw of Darla McGee.
Darla was spoon-fed fire and brimstone every hour of the day by her father, the town's southern Baptist preacher. Now in her senior years, she fancies herself as a minister to her old high school classmates, using their confessions and the fear of Hades to hold them under her thumb for inequities she's felt all of her life. Darla hates two things in particular, the old retreat and Edwin Kranz. And just when the building was about to be torn down, Edwin bought it for a new use.
The opportunity that Ellie hoped for was short-lived. Wasting no time, Edwin springs his plan into action and talks Ellie into opening a nursing home using the old retreat. With everything to be done, she feels as though she's lost the opportunity she'd waited so long for. But that was about to change, because the people moving in are all former classmates of Edwin's and their recollection of him was far from the stoic, stiff upper lip grouch that she knew. What's worse, they're ready to go into explicit detail of his rascally ways.
From opening day it's was mayhem at Kranz Gardens, the name bestowed on the retreat, and quickly becomes a battleground of souls between Edwin and Darla. Edwin becomes the protector of his old classmates while spurning Darla's attempts to hold him accountable for an old scandal with her best friend, a woman he'd shared one intimate night with at the resort while home on leave.
Edwin's old classmates take over Kranz Gardens quickly and if not for Ramy Vicnair, Ellie might have forgotten what sanity looked like. Ramy, the son of Edwin's old Marine buddy, was a soft spoken man from the bayous of Louisiana with a gift for cooking and common sense. As the chef, he keeps everyone happy with savory foods while stirring up a little romance for himself.
Kranz Gardens fills quickly to the point that more help is needed. Edwin places an ad for an additional nurse and hires her immediately when he finds out her mother is the woman who broke his heart making him the man he is today. Ellie is disheartened by the hiring, feeling that her father has lost confidence in her. However, she quickly finds the new nurse to be an asset, a friend, and more.
Throughout Old Flames and Brimstone are combined themes of atonement, forgiveness, and retrospect that happens as people age. When the characters stop taking themselves seriously, they can easily see beyond each others flaws. It's a time to reflect and laugh at their past while looking forward to making the rest of their time count.