I had just finished writing two medieval-style fantasy novels, "The Dark Lady" and "The Queen's Pawn," and was looking to do something different for a break of pace. I decided to try writing an off-beat novella-length fantasy detective tale.
For my inspiration, I decided to take an existing mystery title (Agatha Christie's "The Mousetrap" which I had recently seen on stage in London England. ) muck about with the title, and use the result to design the plot. The "Housetrap" was born, and I had no idea what a housetrap was. Figured the plot out, wrote it, and sent the manuscript off to a publisher, who like the story but said the novella-length was too long for his magazine.
My solution was to write two more using the same format, and "Dial M for Mudder" and "House on Hollow Hill" were born. Now I had a novel-length manuscript. Two publishers liked the trio and then sat on them for two years, the third publisher said, "I'll take it," and the Housetrap Chronicles series was born.
Ten published novella's later, first as ebooks, and then gathered into print collections of three novellas, I'm still using the same format, mess with a familiar title, then figure out the plot from there. I often said, "I throw in everything but the kitchen sink." In #9, "Silence of the Sands" I even managed to do that. Housetrap #11 is now at the publishers and expected to be released in 2021. Housetrap #12 is complete and should be off to the publishers in the next month or two, with a probable release date in 2022. The plan is that will wrap up this series.
But of course, I do enjoy writing them, so you never can tell.