The book has some parallels to incidents and settings of a round-the-world work trip taken by Christie with her first husband Archie Christie and headed by his old teacher from Clifton College, Major E. A. Belcher, to promote the forthcoming 1924 British Empire Exhibition.
Christie found Belcher "childish, mean and somehow addictive as a personality: 'Never, to this day, have I been able to rid myself of a sneaking fondness for Sir Eustace', wrote Agatha of the fictionalised Belcher, whom she put into The Man in the Brown Suit.