How a theater collective transformed the too-weird-to-be-true story of a World War II counterintelligence scheme into a West End musical with heart.The inflatable tanks had to go.At one time, those tanks were a feature of “Operation Mincemeat,” a punchy, plucky, highly unlikely West End musical, which tells the even more unlikely story of an MI-5 escapade. It describes how, in 1942, British Intelligence outfitted an unclaimed corpse as a member of the Royal Marines and delivered the body to the shores of Spain, trusting that German sympathizers would study faked documents planted on the body. It worked. That was hardly the craziest part.“Part of the joy was that the crazy stuff was all true,” said Natasha Hodgson, a member of the theater collective SplitLip, which created the show.But there was so very much crazy stuff. And during early performances, the audience had doubts. They especially doubted the dummy Sherman tanks, which the Allies created to misdirect the Germans. So the tanks were cut. As were other details.“We had to take the truth out because it was too silly,” the composer Felix Hagan, another member of SplitLip said.This was on a recent morning in London. The show’s four creators — Hagan, Hodgson, David Cumming and Zoë Roberts — had gathered in the lobby bar of the Fortune Theater to discuss, excitedly, how a glam punk musician and three writer-performers previously known for bloodpack-heavy horror comedies had created the feel-good West End musical of the summer.The musical’s dozens of roles — secretaries, sailors, spies — are played by just five performers, including Roberts, Cumming and Hodgson.Matt CrockettCumming, Hodgson and Roberts met more than a decade ago, at the University of Warwick, bonding over a shared love of horror movies. With two other classmates, they created the devised company Kill the Beast, which specialized in unusually gruesome comedy, sometimes involving werewolves.The company had several successes at the Edinburgh Festival Fringe. “But it was quite clear that we were going to stay niche,” Cumming said. Shows about tentacled beasts and children devoured by rats were never built for the mainstream.Music had always been an integral component of Kill the Beast shows, which made a full-scale musical an almost logical next step. As Hodgson and Hagan were in a band together, inviting him on as a composer made sense, too. With his addition, SplitLip was formed. What was missing? A story. Which Hodgson found on a family holiday when her brother encouraged her to listen to an episode of a podcast detailing the events of Operation Mincemeat.“I was just like, oh my God, this is the craziest, most amazing, hilarious, horrifying story I’ve ever heard,” Hodgson said. In other words: Perfect. She told her colleagues that they were going to have to write a musical about World War II. No tentacles necessary.There was brief dissension. (Cumming described a World War II story as “the least cool thing you can do.”) But on learning the details, everyone was persuaded. Because, as a character in the musical would later say of the Mincemeat plan, “It’s bizarre, it’s disgusting, it’s borderline psychopathic.”On the strength of a scene and two songs, the show was booked into a five-week run at London’s New Diorama Theater. Which gave the company a hectic and unglamorous nine months to write it. Some of that writing was done in an unheated studio space. The collaborators would take turns riding an exercise bike, just to keep warm.There were several discussions about musical style. Hagan had considered restricting himself to period forms, then rejected that restriction. The resulting score is eclectic, moving among pop, R&B, stride piano. The song that closes the first act transitions between sea chantey and electronic dance music, the EDM a play on a submarine’s pinging sonar.“We needed to make sure it didn’t feel old,” Cumming said.Cumming, Hodgson and Roberts knew that they would star, for financial reasons as much as creative ones. They auditioned for two more singers, a high tenor and a high soprano, then began to divvy up the dozens of roles — secretaries, sailors, a Russian spy, Ian Fleming — among the five performers, with men often playing women’s roles and women playing men’s, without camp or fanfare.“It’s a quietly queer show,” Cumming said. That queerness helped to complicate the story, chafing against its wealthy white male triumphalism by showing who was and wasn’t allowed to make decisions, who was and wasn’t given credit.In writing the script, they agreed to never change the story’s facts, even as they allowed themselves a playful approach to the characters. Yet the facts were often incredible. After an invited dress rehearsal, SplitLip read through feedback forms, some of which scolded the company for lying about history. (“The dads,” Roberts said, “can be very defensive about the war.”)They hadn’t lied, but they had jettisoned the tanks and other particulars: MI-5 employees cosplaying the fake marine, a near car crash on the way to the submarine, courtesy of a blind driver.Still, the show that debuted at the 80-seat New Diorama was a shambolic one (one song lasted about 25 minutes), with an unwieldy second act rewritten just days before opening. The company didn’t really know what they had.“I liken it to getting dressed in the road,” Hodgson said. “Our first performance just felt nude. Like, ‘Is this good?’”The audience thought so. Producers agreed. There were conversations about where the show might go from there.“That’s the first time anyone’s ever said that. Usually, they’re just like, Cool, what’s next?” Cumming said.“Funnily enough, at our werewolf comedy, tears did not flow,” Roberts said. “We were still taken aback by how passionately people cared about these characters and felt for them.”Ellie Smith for The New York TimesThe show transferred to other London venues, Southwark Playhouse and Riverside Studios. A half-hour was cut. (It now runs just over two hours.) That 25-minute song was drastically shortened. At the New Diorama, the show’s creators discovered that audiences connected with the story’s emotional beats and that they wanted more of them. This was a surprise.“Funnily enough, at our werewolf comedy, tears did not flow,” Roberts said. “We were still taken aback by how passionately people cared about these characters and felt for them.” Initially “Operation Mincemeat” had leaned away from emotional moments, undercutting them with jokes. Increasingly, the show leaned in.For the West End transfer, a director and a choreographer were hired. A “glitzy finale” was added. A larger cast was mooted, even a chorus, but the creators realized that the frenetic, quick-change, make-do-ness of the show was much of its appeal and a kind of slant rhyme with history. Then, a small group of officers had effected a piece of theater that made the Germans divert 100,000 troops. Now, a small troupe could transport hundreds of audience members into a new world every night.“The Operation Mincemeat story is about giving just enough evidence to the Nazis to make them believe something that isn’t actually there,” Cumming said. “That’s exactly the same game that we’re playing. Just five people onstage giving you enough clues here and there.”The reviews for the show have been ecstatic. And despite some characteristic British modesty, the creators think they understand why. Even as the show, through its casting and satire, is unsympathetic to the conservative structures of British intelligence, it is ultimately admiring of the very English ingenuity and eccentricity of the people, almost exclusively straight white men, who birthed and accomplished the plan.“We want to celebrate the things that they did while being incredibly aware that the opportunities that were given to do all this were because of a system that allowed them, and no one else, to have those opportunities,” Hodgson said.It’s a tricky balancing act, this patriotism and this skepticism. But a company of five that constantly swaps hats and jackets is accustomed to acrobatics. Sometimes those hats get dropped. (“Everything has gone wrong every possible which way,” Hodgson said. “There’s nothing that can really throw us.”) But the overwhelming impression is of hopefulness, expansiveness, possibility and joy.“Joy has always been our principle in everything,” Roberts said. “The darker the world gets, people need joy.” More