Sir James’ eldest son, James, was born in 1878. He worked in the family business and married Agatha Christie’s sister, Madge Miller, in 1902. They had a son also James, and known as Jack, born in 1903. Like his father, James was interested in architecture and extended Abney Hall with architect and interior designer George Faulkner Armitage in the 1890s. As manager of the Kinder Estate, he was an active president of The Peak District and Northern Counties Footpaths Preservation society in 1921, and utilised Upper House to a much greater extent than his father due to Madge’s active interest in her dogs and country pursuits. James and his sister-in-law Agatha formed a lifelong friendship that often influenced her work. Agatha’s daughter Rosalind spent much of her childhood with them and her cousin Jack.

There are three books that are closely associated with Agatha’s northern trips and visits to Abney Hall and the Upper House Kinder Estate, (‘The Mystery Of Hunter’s Lodge’, ‘Hercule Poirot’s Christmas’, and ‘The Adventure Of The Christmas Pudding’), and others that are directly influenced by her cajoling and affectionate relationship with James Watts. They are fondly dedicated to her brother-in-law in the novels after the publishing credits, and make interesting reading.Agatha also dedicated several books to James and Madge’s only son, born in 1903, her nephew Jack, including “The Secret Of The Chimneys” in 1925. The inspiration of Abney Hall with its considerable hexagonal chimney collection is evident!Hercule Poirot was introduced in Agatha’s first book, ‘The Mysterious Affair at Styles’, in 1921. By 1924 he had become a detective genius through the collection of short stories, ‘Poirot Investigates’, in which he solves a grisly Derbyshire murder from his London bed, where he is confined with influenza, entirely by deduction from remote feedback via his trusty sidekick, Captain Hastings.The ingenious tale, ‘The Mystery Of Hunter’s Lodge’ (televised in 1991), was set at a grouse shoot on the Derbyshire moors near Elmer’s Dale, a thinly disguised Edale, on the other side of Kinder from Upper House.Indeed, Agatha draws on many names in the Derbyshire county for places in her novels. Poirot’s friendly rival, the hapless Mr Japp, stays during the Hunter’s Lodge case at the Matlock Hotel, while the shadowy character around whom the plot revolves is Mrs Middleton (derived from the nearby Stoney variety!). Lady Frances Derwent, the Cavendish family, Jack Hartington, Evelyn Hope, Mary Dove and Sylvia Dale, Tommy and Tuppence Beresford, are all names borrowed from the Peakland. Most famously, the name Miss Jane Marple, who made her debut in ‘Murder At the Vicarage’ in 1930, was confirmed by Agatha, that her name was indeed derived from the town of Marple, which she passed through (sometimes on the train) on her way to Hayfield to stay at Upper House.With the 1926 publication of the blockbusting ‘The Murder Of Roger Ackroyd’, Agatha declared herself a “professional writer”, saying that meant she wrote even when she didn’t want to! It rocketed her to celebrity status, part of the pressure perhaps that lead to her 1926 disappearance. This classic, with arguably the most famous ending in crime fiction, is shot through with Derbyshire spirit, for the fiendishly cunning plot (some say downright unfair!) was suggested by James Watts himself after he said that Agatha’s early works were becoming too predictable.

In 1938 she wrote a detective novel especially for James, after he had teased her that she had become “too civilised”. “I want a good violent murder, with lots of blood” he said, and she duly obliged with ‘Hercule Poirot’s Christmas’. The book carries a long dedication to Watts as ‘one of my most faithful and kindly of my readers,’ and finishes, ‘so this is your special story, written for you…your affectionate sister-in-law…Agatha’.

The ‘Adventure Of The Christmas Pudding’, written in 1960 after James’ death in 1957, she dedicates to “all the happy Christmas’s I spent with the Watt’s in the North”. A mischievously macabre Agatha inflicts Christmas Day malaise on an already restless Hercule Poirot via an anonymous letter sent to his room: “Don’t eat none of the Christmas pudding. One who wishes you well.” Even the dialect becomes distinctly Derbyshire.

The peace and inspiration of Kinder inspired her the whole of her celebrated life as “The Duchess of Death”, as she liked to be referred to! Her daughter Rosalind wrote of Upper House in a letter of May 2000, “I do of course remember it well – it’s a beautiful place and looks much the same as far as I can see as it did when I was a child”. As well as those “happy memories” made at Upper House, Agathas’ relationship with the Watt’s is never made more evident than by the fact James Watts took the mystery of Agatha’s disappearance to the grave with him. Their friendship endured a lifetime, both inspired by a moorland landscape which will undoubtedly inspire many more.