Postern of Fate features Agatha Christie’s detectives, Tommy and Tuppence Beresford and is the detective’s last appearance. It is the final novel Christie ever wrote but it is not the last to be published.
Agatha Christie passed away in 1976. This final novel was published in 1973. After reading it, I was a little disappointed as I feel that it is not really up to the author’s standard as compared to the rest of the books she had written.
A code message in a children’s book puts the detectives on to the murder of a lady suspected to be a secret agent. Agatha Christie wrote her first novel towards the end of WWI, where she was a VAD. Based on those type of settings, and in her final days, she may have been thinking a lot about the past as in secret agents, traitors and commanders when she penned this novel.
As for the ending, I don’t really think of it as a mystery. It is just a collection of past.
According to The Cambridge Guide to Women’s Writing in English, this novel is one of the “execrable last novels” where Christie “loses her grip altogether”