Serendipity- the faculty of making happy and unexpected discoveries by accident (OED)
Do you think of serendipity as random good luck?
Gert did too until she actually read the Persian fairy tale The Three Princes of Serendip from which the word comes. Horace Walpole put us on the wrong track when he described the three princes in the tale as “always making discoveries, by accidents and sagacity, of things which they were not in quest of”. In fact the three princes were an early version of Sherlock Homes, using keen observation to make inferences about a stolen camel that turned out to be true, amazing everyone. So there was nothing flukey about it.
Voltaire has a variant of the story in Zadig, and Wikipedia says Edgar Allan Poe in his turn was probably inspired by Zadig when he created C. Auguste Dupin in “The Murders in the Rue Morgue”, calling it a “tale of ratiocination” where “the extent of information obtained lies not so much in the validity of the inference as in the quality of the observation.” Poe’s M. Dupin stories mark the start of the modern detective fiction genre. Émile Gaboriau, and Arthur Conan Doyle were perhaps also influenced by Zadig.
That said, not all detectives are as coolly reasonable as Sherlock. There’s more than a little serendipity in the random sense in Chandler’s Philip Marlowe, don’t you think?
Gert Loveday's Fun with Books 
Oh dear, I thought my mystery story which begins with a stolen camel was original. And I haven’t read ‘The Three Princes of Serendip’. Perhaps I’ll be accused of plagiarism! It’s too late to do anything about that now. As a mystery writer i consider serendipity to be a very comforting fall-back position, and I enjoy detective novels where the protagonist starts following one set of tracks only to end up following different ones entirely.
Your hitting on the idea of stolen camel must surely have been serendipity in the OED sense. Speaking of “comforting fall-back positions”, have you read Jane Sullivan’s article in today’s Age about rules for writing detective stories? Ronald Knox said, ‘No Chinaman must feature in the story’. Twin brothers were frowned upon and super-criminals and trapdoors must be used with “seemly moderation”. No Chinamen, twin brothers or trapdoors in your camel book, I hope. Different people made up different lists of rules; I’m going to do a bit of reading and put up another post about it.
Why all the interest in stolen camels?And now you you say there are rules for writing detective stories? Won’t that spoil the spontaneity of the plot? Won’t it make everything predictable?
Leslie
You mean camel-stealing isn’t the plague in Canada that it is here? As for rules, writers love to make them – it doesn’t mean anyone takes any notice.
So it’s still the wild west in writing?
Leslie
The interest in stolen camels is entirely serendipitous, Leslie, except that Gert has made me anxious about having pinched someone else’s plot. I haven’t read the Jane Sullivan article, but talk about angels on pinheads! There’s been a long discussion recently on my Linked In Crime writers group about ‘soft-boiled’ detective fiction, and all the different gradients thereof. It’s enough to make your head swim, literally.