While full of fine shows, a long-awaited binge was also full of stress about how loosely audiences followed rules about staying healthy in a pandemic.LONDON — On the February morning when England’s National Health Service pinged me, saying I’d been identified as a contact of someone who had tested positive for Covid, I freaked out completely.Not out of fear of getting sick; I’m boosted, and I think if I got the virus I would probably be fine. But the last time I came to London, in September, my euphoric playgoing trip was thrown into disarray when I tested positive post-arrival, which banished me to a hotel room for 10 solitary, asymptomatic days. Was I about to get stuck here again?I’d only seen one friend this trip and he was OK, so it had to be a stranger, this person with Covid. My mind scrambled to figure out where our paths had crossed. Based on the time frame that the N.H.S. suggested, I would bet it was at a small, crowded theater two nights earlier — my prime suspect being the guy in front of me who’d sneezed mid-show. That’s when I noticed he wasn’t wearing a mask.Which made him pretty unremarkable here, in a city with genuinely world-beating theater but audience Covid safety protocols ranging from lax to cavalier, and getting looser. Over my 12-day visit, which included some gorgeous productions I am grateful to have seen, that lack of stringency dampened my anticipation of shows, my enjoyment of them — and ultimately my interest in going to them.Because even in this not-yet-over pandemic with its ever-shifting rules, I’m used to feeling safe at the theater; used to feeling like we are all looking out for one another, trying to keep everyone onstage and backstage and in the house healthy, in pursuit of this art that we love. It’s not a minor thing, this feeling; it’s rooted in empathy.And on a purely practical level? We Americans do have to test negative before we’re allowed to fly home — on planes that are still nowhere near as crowded as they used to be.TRAVELING TO SEE THEATER is one of those prepandemic habits that has yet to return for most of us, and it’s been driving me a little bit crazy.I am one of those people — maybe you are, too — who reads the news about which plays are being done in which far-flung places and aches to be in the room with them, burns with envy of those who can be, keeps checking and rechecking the mental calculus of “Can I risk it yet?” against “Can I bear one more second not to?” Evelyn Miller and James McAvoy in “Cyrano de Bergerac.” The production was wonderful, but the audience at a return performance — not so much.Marc BrennerSo when my editor, wanting a profile of the actor James McAvoy, emailed to ask if I would be willing to do the interview in London, where he is starring in Jamie Lloyd’s electrifying production of “Cyrano de Bergerac” in the West End, my answer was an all-caps, unfettered yes. It is one of my favorite cities, and I missed it. The time to risk going, it suddenly seemed, was now.I would need to see that “Cyrano” again — twist my arm — because it had been more than two years since I’d caught it in early previews during its original run. To take full advantage of the slog across the Atlantic, I would stay a while and see a slew of other shows — starting, just hours after passing through customs at Heathrow, with a matinee chosen to go easy on my jet-lagged brain.That was “& Juliet,” a pop-musical riff on “Romeo and Juliet” at the Shaftesbury Theater, where we did have to show proof of vaccination or a negative Covid test to get in, and the people near me were wearing masks. It was a jolt, though, in a more than century-old West End theater that couldn’t be described as airy, to see whole groups of people walk in and take their seats barefaced.Assembling onstage before the performance began, the actors did try, in a spirit befitting their frolic of a show, to encourage safer behavior. One briefly held up a chalkboard with a hand-lettered message: “Hello,” it said, which got cheerful hellos back from the crowd. Another brief chalkboard, another message: “Thank you,” which got some applause.But the wordless chalkboard in between those two — bearing a friendly pastel drawing of a mask — got only silence. Which, in the circumstances, counted as a response.“& Juliet” turned out not to be my cup of tea. Still, I’d have stayed if I’d been able to stop thinking about the ventilation, wondering what I was breathing and whether it was worth it.I decided it wasn’t and fled at intermission, back onto the street, back into the open air.Heather Forster and Samuel Creasey in “The Book of Dust: La Belle Sauvage.”Manuel Harlan“THE BOOK OF DUST: La Belle Sauvage,” that night at the Bridge Theater, was leagues more rewarding. Adapted by Bryony Lavery from Philip Pullman’s fantasy prequel to “His Dark Materials,” and staged by Nicholas Hytner with beguiling visuals, it’s the character Lyra Belacqua’s origin story.The stagecraft is more enchanting than the narrative, but what marvelous stagecraft it is: projections conjuring a watery world, life-size boats moving through it with a choreographed fluidity more persuasive than I’d ever witnessed onstage. And of course the spectral puppets, glowing from within.The lovely guy next to me, masked when he wasn’t snacking, told me he felt perfectly safe at the Bridge precisely because it was airy — not like some old West End house, he said. Until that evening, he hadn’t been to any theater since the pandemic began. (You can see “The Book of Dust,” whose Bridge run has ended, in a National Theater Live recording.)It makes me happy when I’m in London at the same time as an Emma Rice production. This trip it was her adaptation of Emily Brontë’s “Wuthering Heights” at the National Theater: a 19th-century classic warmed with music and breathed to life as if it had taken as its cue something Charlotte Brontë once wrote about the novel: that it “was hewn in a wild workshop, with simple tools, out of homely materials.”The moor is a kind of Greek chorus in the play, while the storytelling is nimble and full of fun; Katy Owen is comic perfection as Little Linton, the pampered princeling of Wuthering Heights. But when Catherine (Lucy McCormick) dies and Heathcliff (Ash Hunter) cries, “Catherine Earnshaw, haunt me!,” his jagged grief rips through us, straight to the soul.Lennie James, left, and Paapa Essiedu in the Old Vic production of Caryl Churchill’s two-hander “A Number.”Manuel HarlanIn Caryl Churchill’s brisk two-hander “A Number,” given a stellar production by Lyndsey Turner at the Old Vic, every moment of Paapa Essiedu’s beautifully modulated performance has a similar visceral reach, right into the center of us. Opposite Lennie James as a father who secretly replaced his original son with a clone, Essiedu plays three disparate but genetically identical men with an unshowy humanity that pops against Es Devlin’s stylized tomato-red set.OF EVERYTHING I SAW, though, the production that brought me there is the one that left me absolutely stunned. The first time I saw “Cyrano de Bergerac,” on Thanksgiving Day 2019, the production was still a work in progress.This time, I left the Harold Pinter Theater with a sensation through my limbs like an electrical charge. We are all bodies in space at the theater, and I responded to this “Cyrano” on a cellular level.I saw other shows, too: at the Hampstead Theater, Florian Zeller’s weary new psychological drama, “The Forest,” about a man whose seemingly perfect life is blown up by his infidelity (but at least the cast includes Gina McKee and Finbar Lynch); at the Almeida Theater, Omar Elerian’s overlong take on Ionesco’s “The Chairs,” with the reliably first-rate Kathryn Hunter in slapstick clown mode; and, at the Donmar Warehouse, “Henry V,” starring Kit Harington and featuring — this will sound strange, but it is absolutely true — the most entrancing stage rain I have ever seen. I was able to snag a ticket (a terrible one; I spent a lot of time with actors’ butts blocking my view) the day a lethal storm blew into Britain and people canceled plans.Kit Harington, center, in the Donmar Warehouse production of “Henry V.” The theater was one of the few that explicitly requested that attendees wear masks.Helen MurrayI’d canceled my own theatergoing plans earlier that week, when the N.H.S. texted me about that contact and told me to take rapid tests for five days. In my initial flood of anxiety, I nixed a train trip to Bristol and returned my ticket to see Mark Rylance there in “Dr. Semmelweis” — a play about a pioneer in the prevention of needless infection.Then, at the pharmacy, a clerk handed me a free box of seven rapid tests, from the N.H.S. — a perk of pandemic life in England that Boris Johnson, the prime minister, would announce the end of for most people days later, along with other precautions including contact tracing.Apparently I was fine. Each time I took a test, the result was negative — and each time I reported that online to the N.H.S., the automated response reminded me to “wear a face covering in crowded settings.”It boggles my mind that so many theatergoers in London, sitting side by side for hours, don’t bother with that elementary precaution — if not for themselves, then for the actors, who are not masked, and for other people in the audience who might be medically vulnerable, not able to be vaccinated yet or in close contact with people in either of those groups. It is such a simple kindness. It is also an act of inclusion.The only theater that I saw actively request it was the Donmar, and people complied. Elsewhere any such request was timid, and certainly not face to face. When major West End theater operators said recently that they would no longer require mask wearing or proof of vaccination from audience members, I had to wonder how a mask policy could count as mandatory if it had gone unenforced.One night I went to the Duke of York’s Theater to see “The Ocean at the End of the Lane,” an adaptation of the Neil Gaiman novel. The show hadn’t started yet when I noticed that the guy on one side of me wasn’t wearing a mask. Then a barefaced guy sat down on my other side. I thought: If this were the subway, I would get up immediately. So I left.HOW DOES A CITY — or an industry — that wants to welcome the world and its wallet not worry about things like that? The contrast between playgoing in New York and in London isn’t about quirky cultural differences. These are fundamentally divergent ways of navigating the pandemic.One is cautious, cognizant of the frailty of bodies; of the gaps that remain in our knowledge of Covid and long Covid; of the fact that we learn of new variants only after they start spreading. The other seems heedless — telling the audience, in effect, that they can take their chances or stay home. I wonder how many people, surveying the options, have decided to keep their money and keep safe.I spent a bit more of mine, returning to the Pinter for “Cyrano.” A good single seat had opened up, and I grabbed it. I didn’t want to wait until the show got to Brooklyn to see it again. But I wish I had.The audience was, hands down, the most overwhelmingly barefaced I had seen. I kept looking at the performers, doing their jobs so gloriously on that stage, and wondering how anyone could be so reckless as to gamble with their health. That’s not a right that a ticket ought to buy you.The next night, my last in London before I flew back to New York, I didn’t go to the theater. Unthinkably, it had lost its appeal. More