At first I thought it was a Maggie Smith, Downton Abbey moment. Olda, Madam FitzGerald, widow of the Knight of Glin, describing my pick-up at Limerick station wrote: “It will be either Tom Wall, the gardener, or my son-in-law Dominic. You will know Dominic by his cheery, brown face.” Like I wouldn’t know him from his starring roles in The Affair, The Wire or The Hour. For the cheery, brown face belongs to Dominic West, actor husband of Catherine, Olda’s eldest daughter. If the understatement seemed eccentric, I was soon to learn that mischief is Olda’s default mode. A brave one, given that the glamour of Glin is imbued with loss. My trip, nonetheless, was drenched in theatre.

The drama began with Tom Wall, friend of the family for 30 years. On the drive, he tells me of a childhood spent at Glin Industrial School, which closed a decade before the Knight and Olda came to bring new life to the castle and the village. It is a story which purges the soul with pity and with terror. Clerical abuse survivor, internationally acclaimed actor and Anglo Irish family – this is no one dimensional Downton, here are the rich layerings of Ishiguro’s Remains of the Day.

Tom brings me to the family kitchen where the table is set for four. Catherine greets me and while we wait for the others, she provides a prologue: Glin must be sold. The landmarks of her life are here. And her roots. “We would go on picnics across the river. Daddy would recite poetry, declaiming against the sleeting rain.” Who wouldn’t hope for a never-ending number of days in this place. The Knight’s death, in 2011, sounded the knell. The sense of an ending is palpable. “Truly terrible,” she murmurs as we look over the gardens. The celebrated “working walled garden,” of flowers and vegetables, sparked her mother’s book Gardens of Ireland and her own passion. Currently landscaping Hillsborough Castle, Catherine longs for southern Irish gardens.

Olda arrives, swiftly followed by Dominic, who, despite his size, slips imperceptibly into place, never distracting from Olda. The art of the actor is inescapable, something exploited by former Arts Minister Jimmy Deenihan, who finding Dominic in situ a few days earlier, grabbed him to read the Proclamation at Ballybunion’s 1916 Commemoration ceremony.

Centenaries are in the air. Vogue is 100 years old this year and Olda, whose first job was there, has contributed a memoir. “Editorial was so snooty. They looked down on everyone. I went off and learned to type, then I went to Florence and got a job at Pucci and when I came back to Vogue I found myself in the Men’s section with a Mr Fish, which was very nice.”

Olda’s life, since Desmond’s death, is spent between Glin, Dublin and London. The 35 years of incessant work restoring the dilapidated castle to its neo-classical glory, a home where, ironically, their happiest days were “when we ran it as a hotel,” are, emotionally at any rate, parked. “I’m leaving this life,” she says. “I have to make a different life.” And as is the wont of one starting a new life late in life, the past becomes a starting point. A past where a Major’s daughter found herself in the heart of swinging London. “Everything was very exciting. Though not as decadent as people thought, even at the time.”

Olda’s recollections come in delicate fragments, perhaps to disguise a life which was more challenging than is perceived. When she met dashing Desmond FitzGerald, Knight of Glin, he was still grieving the break-up of his marriage to French beauty Loulou de la Falaise, famous muse of Yves St Laurent. “What went wrong between them was very sad – she was obsessed with clothes and he was obsessed with old furniture.” Her gift for mordancy is as apparent in her description of their new romance as in her husband’s previous marriage. “Desmond had a cousin whose husband suffered from depression. This being the 1960s, the doctor prescribed parties. Every two weeks, great parties. Although he was dating someone else, Desmond invited me. We went out for over a year.” During that time, Olda and Loulou became fast friends and remained so until Loulou’s death in 2011. “I suppose it is unusual to be friends with your husband’s first wife.” Preternatural wisdom? Pragmatism? It was to be a combination drawn on many times in her extraordinary life with the Knight. “We had two small children and Desmond was very sociable: it would be parties every night. It suddenly became apparent we would have to leave London. In 1975, we put the children in a car and came here. We settled down and Honor arrived. Desmond had got the job as Christie’s representative. We travelled around the country, valuing.”

She went everywhere with him. “I had to keep an eye on Desmond.” Mischief or mordancy? The fact is, their’s was a great collaboration, which reached its apogee in her nursing him in illness. “Being ill was a wonderful experience for him,” says Catherine in an astute, elegiac moment. “There was always someone for lunch: he saw how he was valued.”

Our lunch – the most delicious roast gammon and cabbage I have ever tasted – has been punctuated by the children, Dora, Senan, and Francis, seeking sidebars with their father. I sense dramaturgical moments: a play is to be performed. “This is a great house for entertaining,” says Catherine. “Robert Graves came, Paddy Moloney was a great friend. Daddy lived intensely. He filled every corner of every room. It was always fun.”

Suddenly, the play is the thing. We repair to the great hall for the children’s performance. It’s a play within a play – a ghost story, but unlike that other play about a ghost, it does not end with bodies strewn about the stage. It’s full of life. Like Olda FitzGerald.