The world is very different from the way it was just last week. The Russian invasion of Ukraine is being talked about as the largest military action in Europe since World War II.

But my most recent post was part of my series on the book “How to Write a Mystery.” My next one will be, too. But first, I just want to write about why I want to stick with the topic.

One of several other books I have about the history and craft of writing mysteries (or detective stories, as some prefer to call them), “The Golden Age of Murder” by Martin Edwards (London, 2015, Harper Collins), describes the state of society after World War I and as World War II loomed. One of the more biographical chapters, “Echoes of War,” describes the effects of the war on Mac Fleming (husband of Dorothy L. Sayers) and Monty Miller (brother of Agatha Christie).

So how could stories about murder become known as games in those previous ’20s? Edwards wrote, “The bloodless game-playing of post-conflict detective stories is often derided by thoughtless commentators who forget that after so much slaughter on the field of battle the survivors were desperately in need of a change. For a decade or so, detective fiction offered no so much cosiness as a form of convalescence, until people were ready to write and read about terrible events on the field of battle.”

Convalescence sounds good right now. Detectives in stories have solutions at the end of the book, and I can tell how soon the solution will come when I look at where my bookmark is.

The great writers from “between the wars” stayed active to various degrees during the second war. Agatha Christie wrote “Curtain” and “Sleeping Murder,” the last cases for her detectives Hercule Poirot and Jane Marple, respectively, during World War II in case she died in the bombings — but she died in 1976.

So puzzles with solutions can feel good when the world doesn’t seem to be providing solutions. Checking on the explanation in Edwards’ history of the genre makes me feel better today as I go from listening to Rhys Bowen’s Constable Evans solving murders in Wales to reading Laurie King’s Mary Russell (and her husband, Sherlock Holmes) investigating in 1920s Morocco.

Whether I’m listening to the story or reading it, I feel better than the more literally mysterious stories from Ukraine — and elsewhere — on news broadcasts.

So I’ll go on with “How to Write a Mystery.” Its essays may introduce you to new authors, and thus new puzzles. Also, it’s so logical — and I’m sure I’m not the only person starving for logic just now,