“I may be wrong. But frankly, I doubt it.” That line, or words to that effect, are a common refrain on “Murder, She Wrote.” It takes a certain amount of flinty self-confidence for a character to pull that off without sounding smug. We live in uncertain times. Hollywood is in its flop era. But when all else fails, there’s always Jessica Fletcher. No matter my mood or what other TV offerings may be available, I find myself returning to “Murder, She Wrote” over and over again, at least once a week, spotting new details in episodes I’ve seen countless times before. It is my comfort watch, but it has also been instructive for me as a TV critic. Once you start analyzing the show’s various components, it becomes clear that too many of those elements are missing from more recent case-of-the-week procedurals. These basics were once considered standard but I suspect writers are out of practice. For the last decade or so, they’ve focused on the short seasons and serialized format of streaming endeavors. But writing 22 crackerjack stories a year? A lost art, I fear. “Murder, She Wrote”  — which celebrates its 40th anniversary on Sept. 30 —  ran for 12 seasons on CBS and wouldn’t have worked half as well with another actor. Angela Lansbury built her career playing all kinds of eccentrics on stage and screen. But with “Murder, She Wrote,” she understood that wasn’t needed. Give us a personable woman with a good head on her shoulders and let compelling writing do the rest. The premise is simple but wildly effective every time: Mystery novelist Jessica Fletcher goes about her day — whether at home writing or out traveling the world — when someone turns up dead. Suddenly her common sense and all that background research for her books comes in handy. Sometimes she has a personal connection and that’s why she’s compelled to help. Sometimes she’s just aggravated — offended, even — by incompetent police work. Either way, she’s going to get to the bottom of things. She’s dogged and not above a little subterfuge. But she always comports herself with class, no matter how lurid the circumstances. There’s something so thrilling when you come across an old show and belatedly realize it’s good. Really good. That happens often with “Murder, She Wrote,” which people seem to discover and rediscover with a wonderful frequency. “Started ‘Murder, She Wrote’ for the first time,” said the comedian and writer Becca O’Neal recently. “Thought it was about a nosey lil’ old lady. Oh no, Miss Jessica Fletcher was an It Girl.” Jessica is practical but cosmopolitan. Smart but approachable, and compassionate when the circumstances warrant. Infidelity and corruption do not shock; she’s too well-versed in the human condition to be naive about any of it. She never doubts her self-worth or instincts, nor does she let fame go to her head. She’s not impressed by wealth, though her own wealth must be considerable. Even so, we never see a wayward relative come out of the woodwork looking for money and she never splurges on any updates to her chocolate box house in Maine. If asked about her finances, she would probably demure and simply say she’s “comfortable.” She always looks put together and just so but her wardrobe became noticeably more sophisticated a few seasons in, and even by today’s standards she never looks out of style thanks to the classic cut of her tailored skirt suits and pant suits. No one ever refers to her as old, nor is she portrayed that way. She’s surrounded by people of all ages and she makes friends easily. Men are interested! (She usually laughs off their flirtations.) She is comfortable in pokey small towns, glamorous ski chalets or fast-paced urbane settings, and eventually she buys a pied-à-terre in New York. She’s always at work on her latest novel, with no signs of slowing down. She lives a full life! And she’s a character who fits in anywhere, regardless of the company, which is why a crossover episode with “Magnum, P.I.” from 1986 somehow works. O’Neal is right, she really is an It Girl. The show’s writing, though, is just as key as Lansbury’s performance. Great television “brings you in, keeps you there and lets you go satisfied,” said the screenwriter Javier Grillo-Marxuach in an interview last month. He wasn’t talking about the “Murder, She Wrote” specifically, but more broadly the kind of dramas like it that were once the bedrock of television, telling a new story each week and then bidding you adieu — letting you go satisfied — until next time. Somehow that format has deteriorated over the last decade or so. Streaming rode the prestige wave launched by HBO, and ongoing storylines, parceled out chapter by chapter, became the default. Suddenly, the skill needed to write stand-alone episodes — short stories, really — was less in demand. There aren’t many shows of this type anymore, but the handful that have premiered in the years since have a sad trombone quality to them. The mysteries are poorly constructed, the writing hacky and immature. Audiences watch anyway because we are desperate for the pleasures offered by this genre, but these efforts are too often a simulacrum of better shows that came before. It’s not like “Murder, She Wrote” was trying to be anything other than easy viewing, but it was written with real intelligence, complexity and wit. Jessica is as steady as they come, but occasionally the writers carve out room for Lansbury to show a broader range of her talents, whether she is playing Jessica’s daffier British cousin, the music hall singer Emma, or briefly posing as a barfly in order to get some information out of a sports bookie. Those moments reveal Lansbury’s looser side, but she was brilliant actress when it came to drama, as well. In one episode, Jessica has to contend with the possibility that her late husband had an affair and fathered a child while serving overseas. Her pain is very quiet and very nuanced, but she is shaken to the core. That’s a rarity, because otherwise she’s rarely off her game. We never know the character’s age, but Lansbury was in her 60s for most of the show’s run, and Jessica is undaunted by anxieties related to technology. My Tribune colleague, the sports writer Shakeia Taylor, reached out recently with this observation: “I’ve been watching ‘Murder, She Wrote’ and I think it’s interesting how Jessica Fletcher was an early adopter of the computer, at least in her TV timeline.” Yes! After spending years writing her books on a manual typewriter at her kitchen table, by the early ’90s she buys a desktop computer and the episode uses this premise as the basis for a murder mystery. It’s a creative way to bring her into the computer age. In another episode, a company has contracted with her to write a virtual reality video game. When her best friend, local doctor Seth Hazlitt, scoffs at the idea, she tells him to get with it — the 21st century is around the corner! In another episode, she’s on a small plane, tapping away on a laptop computer. As a character, she wasn’t one for nostalgia.  She adapts to change and is engaged with the world around her. “She’s a whole human,” as Taylor put it. Not long ago, the architecture critic Anjulie Rao wrote about the series, which, she said, is really about real estate. “Jessica Fletcher may have been investigating murders, but the show explored the anxieties of modern development.” There are countless episodes about one developer or another looking to horn in and exploit an area. They are always up to no good, whether they’ve set their sights on small-town Maine or tearing down a historic brownstone in New York. The show also loves to satirize show business and multiple episodes are set in Hollywood. One is an obvious parody of “Friends.” Another centers on the “Psycho” house at the Universal Studios lot. Another takes place at a film festival in Milan. Her books were always being adapted — and badly, to her chagrin. When a network head pitches her on a weekly series called “The Jessica Fletcher Mystery Hour,” about “the real-life adventures of a crime-busting mystery writer,” Jessica stops her cold with a meta response. “I don’t write gunfights, car chases or bedroom scenes. Who would watch?” So many of us, it turns out. I asked Taylor why she started watching the show. “My new TV came with a channel that shows ‘Murder, She Wrote’ all day.” (The show is also airs in reruns on various cable channels and is available to stream on Peacock; though it aired on CBS, it was made by Universal Television, a subsidiary of NBCUniversal.) “I’ve been watching it for daaaaays,” Taylor said. “There were a lot of actors I recognize on this show.” Bryan Cranston. Courteney Cox. Adam West. George Clooney. Neil Patrick Harris. Jerry Orbach. The show had its favorite actors, too, that was clear — Gregg Henry, Kate Mulgrew, Jeff Conaway, Jessica Walter, to name a few — who would return season after season to guest star in a new role. You buy it every time because the show’s format can plop Jessica down anywhere, allowing for varied locations and scenarios, whether she’s on an archeological dig in the Southwest or visiting a Ben & Jerry’s-esque ice cream company in middle America, or traveling in Russia promoting the latest translation of her books. The show is not trapped by its setting, but follows a wanderlust that allows it to take on just about any kind of premise and be assured that Jessica would fit in somehow. Would it surprise you that fewer than 60 of the 264 episodes take place in her hometown of Cabot Cove, Maine? Angela Lansbury as Jessica Fletcher on “Murder, She Wrote.” (Randy Marcus/NBCUniversal via Getty Images) By Season 6, Lansbury was exhausted, so producers came up with a workaround: Stories anchored by someone who isn’t Jessica Fletcher, though they sometimes include intros and outros provided by her, which is why they’re often called the bookend episodes. The skill level here is off the charts: Introduce a brand new world and a main character who is fully-formed from the get-go, then drop them into a murder mystery that’s as compelling as any Jessica might solve. Audiences didn’t love the idea and after two seasons Lansbury went back to a full schedule. But watching those bookend episodes now, I’m impressed with how they’re executed. So much storytelling economy is required, and yet they feel rich and lived-in. You need to care about these new protagonists instantly, and you do. Any one of them could have led a full-blown series of their own, particularly jewel thief turned insurance investigator Dennis Stanton, played by Keith Mitchell. The character is not possessed of unique talents, except that he’s wonderfully debonair and understands the mind of a criminal, having been on himself. He’s fond of a quip, keeping everything light, but he’s never unkind. And like Jessica, he feels like a real human being, not just a construct. He appears in nine episodes over the course of the show’s run, but the world of his character — with his impossible-to-please boss and loyal but ambitious girl Friday — was such an obvious contender for a spinoff, it’s too bad that never came to be. At first glance, the writing on “Murder, She Wrote” doesn’t stand out. It’s a well-built narrative each time that avoids being self-serious, immature or hacky. This is standard, you think. It’s the job. But then you watch more recent attempts at the procedural format and realize how challenging it is for TV writers today to approximate anything even close. People want procedurals because they fulfill a certain craving. Sometimes you’re not in the mood for the knotty complications of a serialized streaming drama. Sometimes you just want to be told a story, from beginning to end, in a single episode. Sometimes you want a story that allows you to believe, if only for an hour, that we live in a world where fair play exists and the no-nonsense efforts of a retired school teacher-turned-celebrity author can put things right. There’s an old joke that Jessica Fletcher is actually the real killer. How else to account for all those murders every time she’s around? But a different thought comes to mind: How is she not profoundly depressed by all this death that follows her everywhere? Well, she’s not. Because “Murder, She Wrote” is not that kind of show. Jessica is alert and chipper at the start of each episode, as if all the tragedy that came before has been zeroed out. That’s OK. That’s what TV used to promise: Consistency. And “Murder, She Wrote” is nothing if not consistent. Nina Metz is a Tribune critic.