The Murder of Roger Ackroyd
The novel offers more information on Hastings. He did marry his "Cinderella" and did move to South America. Both events were mentioned briefly in "The Murder on the Links". The novel could also serve as a finale for Poirot. At the end, he decides to retire to the countryside and to pursue his new hobby of growing vegetable marrows. This seemingly contradicts "The Murder of Roger Ackroyd" where Poirot was already in retirement and growing vegetable marrows. Zemboy suggests that "The Big Four" was written before "The Murder of Roger Ackroyd". He notes a reference in "" where the writer notes that between "The Man in the Brown Suit" and "The Secret of Chimneys", she had written another novel.