The same, I must say, applies to the Bethnal Green Tube Disaster. With a portion of my novel taking place near London in early March 1943, I set out to verify the respective weather in an online almanac. Mentioned as a side note on March 3 of that year was another tragedy that stunned me. Considered the worst civilian-casualty event of the Second World War, the stairwell crush referred to as “vertical stacking” resulted in 173 deaths and more than 90 injured, all of which went largely unreported at the time for fear it would damage public morale and feed propaganda material to the enemy. The parallel of this unfathomable incident with that of the Italian Hall, including the trigger of what amounted to a false alarm from the firing of a new British anti-aircraft rocket, couldn’t have been clearer.

I often liken historical fiction to “literary Advil” in that, ideally, readers enjoy the sugarcoating of a story while benefiting from the “good stuff” (i.e., history) along the way. To pass along knowledge of both tragedies, and perhaps even inspire others to research more about the men, women, and children whose lives were cut far too short, is an honor I haven’t taken lightly. For this reason, I attempted whenever possible to remain true to history, and only with reluctance did I (at least knowingly) take creative liberties, having to remind myself that the beauty of fiction invites, even requires, such leeway for an imaginative adventure not meant to be a documentary.

On that note, I came to accept that the timeline of the Italian Hall Disaster and World War II were nearly impossible to reconcile in the path of Fenna’s life. After much pondering and debate, I settled on inventing the town of Eden Springs, fashioned after Calumet, bearing a Christmas Eve stampede based on the actual event. Due to the shifted timeline, I made appropriate adjustments, such as transforming the Slavic woman known as “Big Annie” to “Big Vera” and reducing the party attendees by several hundred given the decline in copper mining compared to the booming years of the actual strike.

Other liberties throughout the book include details involving Fenna’s various gadgets. Aside from the timing of their inception are my portrayals, of course, of her inventing them at all. Hutton, along with his team, were the true heroes in this regard. According to his autobiography Official Secret—in which his personality, speech, and exploits practically leap off the page—the Hutton Flying Boots were designed, at least primarily, by him; they did, unfortunately, suffer from the same flaws and fate woven into my story. The soup-can trick, its unconventional crate delivery, and subsequent explosion are all attributed to “Clutty” as well, though the specific air commodore involved has been fictionalized. Likewise, Hutton indeed received an amusingly cheap watch from Houdini, but if he ever in turn gave it away, it obviously wasn’t to Fenna.