One day in the next few decades, everyone who watched World War II happen will be dead: housewives, soldiers, taxi drivers. It's simple math—the addition of time plus mortality—but it feels like a crisis. If nobody is around to directly remember what it was like when a whole nation went mad and tried to take over the world, couldn't that mean the whole infernal nightmare is likelier to happen again?

In his debut novel, HHhH, French author Laurent Binet writes about the process of writing a book about Reinhard Heydrich, a real-life, high-level Nazi nicknamed "the Butcher of Prague." Heydrich was in many ways the psychopath behind the throne; he's widely regarded as the most brutal Nazi in Adolf Hitler's upper echelon of advisers and the intellect behind Heinrich Himmler, and he could be the man who came up with the Final Solution. (The title is an abbreviation for "Himmlers Hirn heiĂźt Heydrich," which was a common saying in Germany that translates to "Himmler's brain is called Heydrich.")

Our narrator finds himself fascinated with Heydrich, so he immerses himself in all the books and movies in which Heydrich (or thinly veiled Heydrich analogs) make an appearance—a nearly forgotten Fritz Lang film, a film starring Kenneth Branagh, a TV miniseries based on a speculative novel written by Robert Harris. Soon he's hoarding secondary and tertiary sources as though they were stamped onto precious metal. Any connection to Heydrich, however tenuous, is enough to capture his attention.

But as it often does, the hunger for research transforms into a desperate quest for primary sources. He frets when he has to invent dialogue because no record exists of private conversations between Heydrich and others. He feels guilty when he writes that the "blood rises to [Heydrich's] cheeks and he feels his brain swell inside his skull," because it's not something that is provable as a fact. He removes the sentence and then, shamefully, inserts it back into the narrative because the line is too good to leave out. When he's not writing, our narrator visits places Heydrich once visited, looking for the kind of insight that proximity can offer, but after so many years, the trail has gone cold. It might as well not be the same world anymore.

But that's the kind of thinking that gets you into trouble. The saying about being condemned to repeat history may be facile and preachy, but it is, on some level, true. Several of the narrator's friends express surprise when they discover that Heydrich was a real person and not an invention. With the exasperation of a true believer, the narrator snaps back, "No, it's not invented! What would be the point of 'inventing' Nazism?" This is, of course, willfully ignoring the fact that somebody already did invent Nazism, and that a very small but very vocal contingent of humans still thinks the invention of Nazism was a very good idea.

HHhH is a meta-novel in the vein of Kundera and Vonnegut, and the arm's-length distance between the book that the fictional stand-in for Binet is writing and the book that he actually writes is an appropriate and intelligent choice. In an age when Holocaust movies and books run the risk of toppling into melodrama, we have to begin investigating the distance between ourselves and the history in order to understand how close to the history we still are.

But the truth is, no novel can capture the complexities of real life, so it's heartening that books full of primary-source material are still being published to remind us of the stories of millions of real human beings who were just like us. Next month, Polity Books will publish Letters to Hitler, a collection of letters written during the rise and fall of the Third Reich. It's nothing like the book you'd expect.

These are real Germans in the 1930s and '40s with real concerns that often had nothing to do with hate or world domination. The executor of a will coordinates the delivery of "a large palm tree" to Hitler because the deceased is "a great admirer of [Hitler's] political efforts." (The executor is cordially informed, "Mr. Hitler would be glad to receive the palm tree.") A proud parent writes that if her 10-month-old daughter "is shown a picture of uncle Hitler she immediately salutes." (If the technology had existed then, you just know it would be a YouTube video.) Other Germans express their frustration at not receiving a personal reply, only to be told that Hitler is very busy and regrets that he cannot give every letter the attention it deserves. It's all so mundane and typical and positively, horribly human. recommended