The Arthur was the creator of Sherlock Holmes, Sir Arthur Conan Doyle. Harry was the legendary escapologist, Harry Houdini. They had been brought together by their shared interest in spiritualism. They met on this occasion in a hotel room in Atlantic City.
The curtains were drawn and the ouija board was produced. Conan Doyle's wife, Jean, allegedly a medium, attempted to summon the spirit of Houdini's mother. As the escapologist and writer looked on she said she had succeeded and conveyed to Houdini seasonal Christmas greetings from his departed mum.
The two men rejoiced at the success of the seance. It was only later that Houdini, no doubt inspired by the spirit of Sherlock Holmes, smelled a rat.
As his mother was Jewish, her first words to her son from the other side were unlikely to be Merry Christmas. And as she spoke only Yiddish it was even more unlikely that she and Lady Conan Doyle would be able to have much of a conversation.
After that evening in 1922 the relationship between writer and escapologist became increasingly strained, developing into a feud. The feud and Conan Doyle's staunch defence of spiritualism is evident in letters by the author to be auctioned today.
The two men fell out for good when Houdini's repeated failure to reach his mother on the other side led him publicly to denounce mediums and seances as frauds. Conan Doyle remained a firm believer in spiritualism.
Four letters written by Conan Doyle to the American journalist and the psychic investigator, James M Bird, are expected to fetch between pounds 3,000 and pounds 3,500 when they go under the hammer at Southeby's.
Conan Doyle was an admirer of Bird's investigations, even remarking in one letter with a surprisingly modern colloquialism "Wow! What a life!"
The letters encourage Bird in his "quest upon the greatest of all questions" and congratulate him on his "stand against Houdini", adding that Bird, after his investigations, "cannot have the slightest doubt of the preternatural origin of these phenomena. Nothing is SUPERnatural."
He also encouraged Bird in his "quest upon this greatest of all questions - so great that the most powerful argument against it is that its general acceptance would dwarf the affairs of life".
Also for sale at the auction is a pamphlet, A Word Of Warning, which Conan Doyle wrote in 1928 saying that the world faced an impending crisis to which he had been alerted through his spirit guide.
Meanwhile, a frustrated Houdini had published a series of articles exposing mediums and psychics as fakes.
Taking issue with one of these, which refers to a photograph of a levitating Chicago medium that Houdini said was false, Conan Doyle wrote: "He told me that he could see the foot of Mrs Tomson in the photo taken with him in Chicago. I should think that the real argument is that where a medium is faking she would take particular notice that her foot was not visible."
Included in the sale is an LP brought out in 1970 of The Final Houdini Seance. That seance, which took place on 31 October 1936, involved Houdini's widow attempting to contact her late husband. She failed.