Books like Difficulties by Ronald Arbuthnott Knox

In 1917, war‑injured Captain Hastings arrives at his friend John Cavendish’s Essex manor, where the wealthy widow Emily Inglethorp is found dead by strychnine. Hercule Poirot is called to untangle a web of family intrigue and hidden motives.

A pioneering English detective story in which a priceless diamond, once stolen from a Hindu idol and presented to a young woman on her eighteenth birthday, disappears again, sparking intrigue and danger.

Walter Hartright, a drawing master, becomes entangled with Laura Fairlie, Sir Percival Glyde, and the scheming Count Fosco as questions of identity and madness intertwine in 19th‑century England.

Lord Peter Wimsey is drawn into the mysteries of a disinterred corpse, uncovering a century‑old crime that reverberates through a quiet East Anglian village.

Horatio Leavenworth, a prominent New York merchant, is found dead in his Fifth Avenue mansion. Suspicion falls on his two nieces, Mary and Eleanore, as only one stands to inherit his fortune, sparking a classic whodunit.

Ronald Knox was one of the most influential British convert-writers of the 20th century. Of his many works, The Belief of Catholics is his best-known book and his premiere piece of apologetics. While it deals extensively with Protestantism, its target is more the unchurched or lightly-church modern who, if he gives any thought at all to Catholicism, thinks it mildly foreign. As Knox knew, it is not the most difficult part of modern apologetics to convince the devoted Protestant that he has much of Christian truth but now needs to move on to the rest, which is found only in the Catholic Church. The most difficult part is convincing the nominal Protestant (or nominal Catholic), the vaguely religious person, or the person without any religious inclinations that God really does exist, that His existence matters, and that only knowledge of Him and obedience to Him can lead to answers to the questions that haunt everyone. Knox discusses "the truths Catholics hold", "the rules Catholics acknowledge", "the strength Catholics receive", and "the ambitions Catholics honour". These truths, rules, strengths, and ambitions were attractive to the book's first readers. They were answers to the ever-present "Why?". These answers will prove equally attractive to today's readers who, after so many decades of failed isms, yearn for understanding and commitment even more than did their grandparents' generation. ~ from Amazon.com

Professor Charles Grimaud is challenged by a stranger who claims to have risen from his own coffin. When the stranger dies violently during a snowstorm, Dr. Gideon Fell investigates a killer who leaves no footprints.

A SPIRITUAL AENEID (1918) is Knox's only autobiography. It was written immediately upon Knox's reception into the Catholic Church. It chronicles the intellectual developments which let to his conversion. Knox himself revised it in 1950 but was mostly content to let it stand as an historical document, only adding a foreward entitled 'After 33 Years'. "In an Aeneid, as in an Odyssey, you may be driven from your course; but, to crown the sense of adventure, in an Aeneid you do not even know where your port lies; you must make experiments, hark back to beginnings, throw yourself upon celestial guidance. Nor is it, as in an Odyssey, the thought of familiar scenes and remembered faces that hurries you on when you are tempted to linger; it is a mere sense of mission, imperiously insistent, that inflames your discontent." - Ronald Knox ~ from the website of The Ronald Knox Society of North America (http://ronaldknoxsociety.com/biography.html)