It’s said that the truth is stranger than fiction, and perhaps that’s why historical fiction has such staying power as a genre. But in the case of authors who write about history’s worst moments, a better saying might be that we need fiction to help us understand the truth.

For Glenn Shapiro, a lifelong poet and short story writer who embarked on writing novels when he retired from the insurance industry, the frightening history of World War II was personal: His father was Jewish, and his mother was a German Catholic who was born in 1941. Luckily, Shapiro’s immediate paternal family was already in America during the reign of the Nazis, and while his mother retained vague memories of sirens and a moment of hiding in a bomb shelter while her uncle rushed upstairs to save her beloved toy bear, she was only 4 by the time the war was over and spent most of her life in America.

And so while Shapiro’s family history certainly has deep ties to the war, he created entirely fictional characters and storylines (save for a certain cherished teddy bear) to populate his novel The Threads Remain. What is true, aside from historical facts, is Shapiro’s focus on the immediacy of these experiences and the ways in which ordinary people were swept up into the Nazi war machine. He opens the novel with an account of a little boy being hidden in a wall by his mother so she can save him from the Nazis:

Everything went pitch black. Friedrich trembled and began to cry but did so silently. He had never known darkness like this. There was no light. He felt the rough back of the paneling against the backs of his hands as they hung by his sides. He tilted his head forward just a few centimeters until his nose felt the same rough surface. He was in a box, between wall studs on each side, the building siding behind him and the paneling before him. In complete blackness.

There was a bang at the door of the apartment. He heard men’s voices and his own Mutti, but they sounded strange to him, shrill and angry. The men’s voices rose louder, followed by a loud crashing that sent vibrations through the wall that Friedrich could feel against his nose. His mouth opened to scream but no sound came out as he remembered his promise.

Little Friedrich is too young to understand what’s happening, let alone have any kind of power over his circumstances. But as he grows up, he and all of Glenn’s other characters will have to use the only agency they have and make the best choices they can, despite terrifying circumstances. Kirkus Reviews calls The Threads Remain “an intricately woven story full of tragedy and hope.”

Shapiro, who lives in Western Massachusetts and wrote a previous novel called Cold Spring, considered writing longer fiction when he first told his wife about an idea for a story that he thought needed to be a full-length novel. But could he actually write it? His wife’s excellent response, “Just try it and see what happens,” led Shapiro on a creative adventure that brought him more success than he’d anticipated. He wrote several thousand words the first time he sat down to work on Cold Spring, which ended up selling over a thousand copies and garnering positive reviews.

Pleased with the result of his hard work, Shapiro embarked on the much more complicated and intricate narrative of The Threads Remain, which he says he “never could have done without writing Cold Spring first.”

The Threads Remain involves multiple characters and timelines, illustrating how our connections with each other can stretch across time, loss, and trauma. Kirkussays that “over the course of this layered narrative, Shapiro demonstrates an exceptional talent for storytelling as he highlights war’s capacity to separate people, but also to draw them together in a common cause.…As the various timelines intertwine, the author’s fine attention to detail results in a satisfying reading experience.”

The Threads Remain is a historical novel with no basis in the real lives of Shapiro’s ancestors, partially because even if the author wanted to make an account of their history, he has no idea what their own experiences were like. What did capture his creative mind was the “time and place” of Germany during and after the war. As a result of his own lineage, he of course thought first about the experiences of the Jewish people, but then he also considered German citizens in the resistance and then actual Nazi soldiers. “In some ways, it’s almost more tragic than seeing a character you love get outright killed,” he says, “to see them turned against who they originally were.”

Shapiro became so attached to the people he’d created that he sometimes came away from his writing sessions with tears in his eyes, heartbroken over the choices that characters he’d created himself were making. But when writers do a good job of building realistic, multidimensional characters, they know what they’ll do in a given situation, even if that choice feels awful.

Over the course of his creative life, Shapiro has learned that even if you start out with an extremely specific idea of what you want to write, the process of writing, and your characters themselves, will often lead you down paths you didn’t imagine. Still, when embarking on a more complicated creative project, you might need to do a lot more planning, and you may end up keeping more of that original skeleton simply because it gives your story cohesion.

“The Threads Remain is so much more complex than my first book,” says Shapiro. “If my first book was 20% my original outline, and 80% was how it got filled in, The Threads Remain might have been more like 40/60. I spent a lot of time outlining, because the timelines are so interwoven and so important for plot points. I have three character groups across three different timelines, and yet all of their lives intersect at different points. I had to decide: When am I going to reveal things to the reader? All those decisions about how I wanted to unveil the story and give it to readers necessitated a lot of outlining.”

These days, Shapiro is 25,000 words deep into his third novel, a near-future cyber-thriller about a hacker and artificial intelligence, but he’s not yet ready to fully leave The Threads Remain behind. Although he didn’t take any real-life inspiration from the lives of his ancestors, the fictional characters he wrote on the page became another kind of family to him. The Threads Remain is already more successful than his first novel, selling over 6,500 copies, but Shapiro’s eagerness to share his story with more people has nothing to do with the numbers. “I just want as many people to read it as possible,” he says. “It’s nothing to do with money. I know it sounds strange, but I feel like I owe it to these characters. I know that they don’t actually exist! But I feel like they do. And I want to share their story.”

Chelsea Ennen is a writer living in Brooklyn.