Pretty much all of my stories involve Locked-Room mysteries of some sort, which usually takes some time to plan. How do you guys plot your Locked-Room mysteries? I usually think of an absurd scenario, a contrived way to make that absurd scenario work, try to make it sound not contrived and then start to think of how to make a story around it. I find that Locked-Room Mysteries are the hardest plot device to use because of the sheer amount of effort that goes into it. It isn't something you can just change at the last minute. Your explanation needs to have airtight logic, or else you are going to lose your reader very easily. What about you guys? Do you like using locked-room mysteries as plot devices? If so, how hard do you consider writing them?