One of the middle series episodes.

“Judging by some comments here, “The Case Of The Missing Will” appears to be an underrated “Poirot” episode. Though apparently loosely based on an Agatha Christie story, it is a quintessentially Christie-ian tale about a old tycoon, a possible murder, a missing will, the search for a heir, deep buried family secrets; the ending is a surprise, but a logical one (the biggest clue can be found in the method of the murder). Gender politics of the 1930s are nicely incorporated into the story, and it is a clever Miss Lemon observation that enables Poirot to solve the mystery. The production is elegant, and the ensemble acting is typically fine, with Beth Goddard a spirited Violet. The only questionable plot point for me was the lawyer’s remark that an oath could be sufficient for a person to claim that he (or she) is someone’s heir; even in the pre-DNA era, I doubt it would be that simple.”