Why didn't they ask Evans? by Agatha Christie

When Bobby Jones finds a dying man during a game of golf, he doesn't realise that it's going to be a life-changing, and nearly life-ending, event. Standing guard over the injured man, Bobby hears his last words, before relinquishing his post to passer-by Roger Bassington-ffrench. Within days Bobby has narrowly escaped death by poisoning, to the mystification of the local police force, who attribute the attempt on his life to a passing lunatic! However, Bobby and his friend Lady Frances Derwent (Frankie) are sure that Bassington-ffrench's appearance so soon after the stranger's death cannot be by chance, so they stage an accident to gain access to his home in order to find out more about him.

Bobby is a young man slightly prone to diffidence, particularly since he has recently had to leave the Navy because of his poor eyesight, an event which has left him at rather a loose end, and subject to the mild disapproval of his father, the Vicar (some of their exchanges are a joy). Distinctly "keen" on Frankie, Bobby nonetheless fears that their class difference makes her unattainable, and he misinterprets her friendly overtures as condescension. Frankie is a forceful young woman, however, and is determined that between them they will solve the mystery of the dead man, and the significance of his dying words.

The story moves at a briskly entertaining pace, and the two young people (and Bobby's rather shiftless friend Badger) are appealing. You know that, without Frankie's driving force, Bobby would simply have drifted along, accepting the police verdict, and would probably have been the victim of a second, more successful, attempt on his life. The denouement is typical Christie, a long exposition and, in this case, not perhaps her most convincing. In fact, I thought I spotted a distinct hole in it, but decided to ignore it in the pursuit of straightforward enjoyment of an amusing story.