On May 17, after two failed tries, London’s theaters hope to reopen for good. Meet a director, a producer, an actor and a costumer, nervously raring to go.LONDON — At 7:30 p.m. on Monday, Maureen Lyon will be murdered at St. Martin’s Theater in London, her screams piercing the air.Her death is a moment many in London’s theater industry will welcome for one simple reason: It’s the opening of “The Mousetrap,” Agatha Christie’s long-running whodunit, and it will signal that the West End is finally back.For the last 427 days, the coronavirus pandemic has effectively shut London’s theaters. Some tried to reopen in the fall, only for England to plunge into a new lockdown before they even got to rehearsals.They tried again in December, and several musicals, including “Six,” about the wives of Henry VIII, reopened to ecstatic audiences. But just days later, the shows were forced closed once more.This time, the comeback is meant to be for good. Prime Minister Boris Johnson has said theaters can reopen with social distancing on Monday and without it on June 21, provided coronavirus cases stay low, thanks to the country’s rapid vaccination drive. Vaccine passports might be required by then — a measure many major theater owners back.A host of shows are scheduled to reopen this month, with Andrew Lloyd Webber’s new “Cinderella” musical coming June 25 and a deluge of others soon after. “Hamilton” reopens in August. What happens to these shows will likely be a bellwether for Broadway’s reopening in September.But what’s it actually like for the theatermakers who are starting work again after 15 months? Has the pandemic shaped the way they think about theater? We visited four to find out.Ian RicksonDirector, ‘Walden’“Work that engages with who we are now.”The director Ian Rickson, right, rehearsing the new play “Walden” with the actors Lydia Wilson, left, and Gemma Arterton.Johan PerssonWhen Ian Rickson walked into a London rehearsal room in April — to start rehearsals for the play “Walden” — he decided he had to perform a ritual to show just how grateful he was to be back in work.So he got some palo santo — a wood shamans use to cleanse evil spirits — and burned it in front of his cast. He’d only performed a ritual like that once before, he said, as he’d been afraid of “feeling like an idiot.”But the actors also wanted to mark the occasion. “Every day now they’re saying, ‘Can we burn some more?’” Rickson said.One of Britain’s most in-demand directors, Rickson’s Broadway triumphs include “Jerusalem” and the 2008 revival of “The Seagull.” (“The finest and most fully involving production of Chekhov that I have ever known,” wrote Ben Brantley in The New York Times.)The night the shutdown hit, he was in a dress rehearsal for the play “All of Us” at the National Theater, while his revival of “Uncle Vanya” was attracting sellout crowds in the West End. Suddenly, he was without work or a sense of purpose. During lockdown last spring, he walked round the West End and cried while looking at all the shut theaters.He kept himself busy by filming “Uncle Vanya,” but said he spent most of the time reflecting on what he wanted theater to be when it returned. His answer: “New work, work that engages with who we are now, courageous work.”“Walden,” by the largely unknown American playwright Amy Berryman, is the first example of that. He came across the play — about two sisters with contrasting views on how humanity should deal with climate change — last summer, while searching for scripts with the producer Sonia Friedman.“It’s kind of dazzling in its imaginative scope,” Rickson said. “It’s like a play by a writer who’s written 20 plays, not a debut.”In the rehearsal room one recent Thursday, the three actors — Gemma Arterton, Fehinti Balogun and Lydia Wilson — lounged and laughed on a sofa together. They all had regular coronavirus tests, so they didn’t have to distance from each other or wear masks. It was almost as if the pandemic never happened.Near them sat piles of props, while the walls were covered with inspirational quotes (“When one does not have what one wants, one must want what one has,” read one).Rickson smiled happily as he took in the scene. He had an almost religious calm to him; the main difference between rehearsing now and before the pandemic, he said, was just how thankful everyone was to be there.At one point, Rickson recalled, he asked the actors to dance, to explore how their characters would behave at their most exuberant. Halfway through, Arterton stopped. “God, I’ve missed this, sweating and dancing with other people,” she said.Rickson said he appreciated that moment, but hoped to see bigger changes to London theater than grateful rehearsals.“The pause has allowed us all to think, ‘How do we want to work?’ ‘Who’s the work for?’ and ‘Who’s part of it?’” he said. “Perhaps even the West End, which can sometimes be the more traditional end of theater, can also be progressive and be pioneering.”“It hasn’t been like that for a while, has it?” he added.Nica BurnsChief executive, Nimax Theaters“We’re not going to make a profit but we’re better off than closed.”A leading British theater newspaper named Nica Burns “producer of the year” for her efforts to reopen West End theaters.Suzanne Plunkett for The New York Times“This time, we feel it’s for real,” Nica Burns said recently, leaning over a table in her West End office, widening her eyes as if to prove it.Britain’s vaccine rollout was “fast by any measure,” she said. “Of course, if we weren’t selling any tickets, I wouldn’t feel so jolly.”Burns, the chief executive of Nimax Theaters, is one of the unsung heroes of the West End’s comeback. Over the past year, many figures in Britain’s theaterland have grabbed headlines for trying to support workers during the pandemic.Lloyd Webber continually harangued the British government to let theaters reopen, even hosting a government-sanctioned experiment in July to prove it could happen safely. The “Fleabag” star Phoebe Waller-Bridge set up a fund to support freelance theatermakers, as did the director Sam Mendes.But Burns did something else: She tried, repeatedly, to open her six theaters with social distancing and mask mandates.In October, she managed to open the Apollo for 14 performances by Adam Kay, a comedian and former doctor, before England went into a second lockdown. In December, she opened several more for just over a weekend, before England went into lockdown again.Her moves were “a landmark moment of genuine hope for the industry,” The Stage, Britain’s theater newspaper, said when naming her its producer of the year. “In the face of overwhelming odds this year, she has consistently tried to make it happen, when some other established commercial producers didn’t.”Now, she’s planning to open them all once more. “Six,” the musical about the wives of Henry VIII, will play at the Lyric. “Everybody’s Talking About Jamie,” a musical about a boy dreaming of being a drag queen, will be right next door at the Apollo.“Six” and “Everybody’s Talking About Jamie” are reopening in Nimax theaters in May.Suzanne Plunkett for The New York Times“We’re not going to make a profit, but we’re better off than closed,” Burns said. “And on the human side, we’re a million times better.”She is bringing back 150 staff members to run the front of house operations. “I can’t wait for the first payday,” she said. “They’ve had to wait a long time for it.”Burns said a key moment in her decision to reopen came in August when she saw a concert version of Lloyd Webber’s “Jesus Christ Superstar” in a park. The night was such a joyful, communal experience, she said; it rammed home what makes theater special. “I sat watching and went, ‘I’ve got to get my theaters open. If he can do it, I bloody can,’” she added.Burns is looking for other ways to help this city’s theater industry. In April, she announced a Rising Stars festival, letting 23 young producers host shows in her venues this summer. The shows include “Cruise,” a one-man tale of gay life in London, as well as an evening of magic acts.She’s also setting up a coronavirus-testing hub for actors and crew at the Palace Theater, normally home to “Harry Potter and the Cursed Child,” which has not yet announced its reopening date.In an hourlong interview, she didn’t dwell on fears that anything, like a new variant of the virus, could jeopardize these plans and plunge Britain into a fourth lockdown. That might partly be because she’s in the West End for the long haul.Stuck to the walls of her office are architectural plans for a new theater — the seventh with Max Weitzenhoffer, her business partner — that’s meant to be built down the road from the Palace.It doesn’t have a name yet, she said. How about the Burns Theater? “No, no, no, no, no,” she replied. She’s naming a bar inside after herself. “That’s enough,” she said.Noah ThomasLead Actor, ‘Everybody’s Talking About Jamie’“I’ve learned that I don’t need to change to please anyone”Thomas, right, had only two months in the title role of “Everybody’s Talking About Jamie” before London locked down.Matt CrockettLast year was meant be Noah Thomas’s big break.In January, he made his West End debut as the lead in “Everybody’s Talking About Jamie,” a hit musical about a gay teenager who dreams of becoming a drag queen.His dressing room was adorned with art from fans, and months after dropping out of drama school to take the role, he had become used to seeing his face plastered on London’s buses. Then the pandemic forced his theater shut, and he found himself at home with his mum, dad and sister.“I went through every stage of emotion,” Thomas said in a video interview. “Frustration, boredom, appreciation for having a rest because I legit haven’t had one since I was five. Then frustration again, then boredom again.”Last June was a particularly low point. He tweeted a picture of a full airplane, alongside one of an empty theater. “It just made me think, ‘Why’s that one OK, and the other isn’t?’” he said. “Every other industry was talking about getting back to work, and we were all sitting at home.”During lockdown, he read a host of scripts and learned to cook pasta dishes and curries (“I’m going to be the meal-prep queen when we go back”). And he spent a lot of time reflecting on who he wanted to be as an actor.“I see the world through a different gaze now,” he said. “I’ve learned that I don’t need to change to please anyone.”Thomas said he thought that attitude would help when the musical returns May 20. Jamie “is so unapologetically himself, and he’s calling for the world to adapt to him and his fabulousness and his queerness,” Thomas said. “He’s not changing.”The show, which has a cast of 26 and a nine-person band, is the largest to reopen next month, thanks to a government grant. Thomas said he knows what to expect in terms of coronavirus precautions, as his show was one of the few to briefly reopen in December.“It was weird,” he said, “but the rules and the mitigations and masks are such a small sacrifice in order to be able to do our jobs.”He had one more task before rehearsals started: to dye his hair blonde. “A lot of people flirt with you when you’re blonde,” he reported. That doesn’t stop even with social distancing.Janet Hudson-HoltHead of wardrobe, “The Mousetrap”“We’ve been going so long. If we can survive this, others can.”Janet Hudson-Holt, the head of wardrobe for “The Mousetrap,” at the St. Martins Theater. She has worked on the long-running show for 20 years.Suzanne Plunkett for The New York TimesJanet Hudson-Holt, the long-serving head of wardrobe at “The Mousetrap,” was trying to do a costume fitting for the actor Sarah Moss — without touching her.It started well. Inside a cramped room at the St. Martin’s Theater, Hudson-Holt handed Moss a heavy black wool coat, then stood back to admire the fit. But within seconds, she had leapt forward, grabbed the rumpled collar and adjusted it.“Sorry!” she said, realizing she’d broken the rules. “It’s just instinct.”“The Mousetrap,” which has been running in the West End since 1952, is scheduled to reopen on May 17, the first play here to do so.“We’ve been going so long,” Hudson-Holt said. “If we can survive this, others can,” she added.Hudson-Holt, who’s been with the show for almost 20 years, had spent most of the past year at home. “We were lucky, as the very good management kept us furloughed,” she said, meaning the government paid a chunk of her salary. “But for a lot of freelancers — costume makers, propmakers, actors — it’s been just devastating.”To lessen coronavirus risks, two casts will now alternate in the eight roles. The show’s website makes that move sound like a canny piece of marketing, encouraging audiences to see both sets of actors. In reality, it’s in case illness strikes; if one cast has to isolate, the other can step in.The extra cast members means Hudson-Holt had spent her first days back sourcing hats, coats and cardigans for them all. Shop closures had impacted that effort, she said. One of her favorite sources for old-fashioned men’s wear is Debenham’s — all its stores have closed.Her daily routine changed in other ways. Rather than taking measurements in person, she called the actors, politely inquiring if they’d gained weight or muscle in lockdown and would be needing a bigger size.“I was having to ask people, ‘Oh, have you been doing any sport lately? Or maybe some baking?’” she said.Despite the no-touching rule, the fittings went according to plan. Hudson-Holt had found a hat for Moss, new to the role of Miss Casewell, one of many potential murderers stuck in an English guesthouse after a snowstorm.Only a lime green silk scarf caused problems. Hudson-Holt tried showing Moss how to fold, then tie it, but Moss was flummoxed. “Can you slow down a bit and show me again?” she said.“Today’s a fun test for everyone,” Hudson-Holt said.Once the fitting was over, Hudson-Holt put Moss’s outfit aside. It would be steamed later to kill any potential viruses. “I know it seems hyper vigilant,” she said, “but who wants to be the one that mucks this up?” More