It's possible that it's often said that it helps a writer to diversify and have experience with many different types of stories. A mystery, then:
There is a mechanism which may result in the death of a cat without any possibility of prediction. However, the cat is not present at the moment. The only way to ascertain whether the cat is living is to examine traces in the environment where the cat has been.
Some of the traces, an incidental result of movement here or a scratched couch there, are not conclusive. The best analysis is unable to conclude they are of recent origin, but even in the case they are several weeks old they only prove the cat existed at the time, and an event to change that may or may not have occurred since then.
But there is also a different kind of evidence, marking unusual behavior for a cat. The question is whether this evidence, left by a cat that seems to be no longer visible, is more likely to have been done by a cat that is currently alive elsewhere, or a cat that is dead..?
Suppose that the motivation for an action is not to prevent someone else from hating something, but to prevent yourself from hating—it, or something else..?