It seems like common sense that once a person has been doing something for upward of 50 years, they’re as good at it as they’re ever going to be. Figures like Meryl Streep or Bruce Springsteen no longer reinvent the wheel with their new art, and they don’t need to – they’re institutions now.

That’s why it’s a little surprising that Stephen King, who’s been an icon of his medium for half a century, has progressed from offering what could generously be described as some questionable depictions of neurodivergent characters to creating one of the most nuanced, well-realized autistic characters in literature, culminating in his latest, “Holly.”

The title character, private investigator Holly Gibney, first appeared in King’s “Mr. Mercedes” (2014). She’s a supporting character in both that and its two follow-ups, “Finders Keepers” and “End of Watch,” assisting retired cop Bill Hodges, and was the main protagonist in King’s novella “If It Bleeds,” from 2020. Holly is not explicitly identified as autistic in the initial volume, but is later described as having “Aspergers-like” tics, and the two actors to have played her on-screen – Justine Lupe in the “Mr. Mercedes” series and Cynthia Erivo in HBO’s “The Outsider” – have both said they deliberately played her as autistic. Lupe’s Holly also describes herself “stimming,” the term for autistic self-soothing behaviors.

In her early appearances, Holly lives in circumstances that will be painfully familiar to many adult autistic people – she’s a middle-aged woman who remains under the thumb of her mother, Charlotte, who has deliberately kept Holly dependent on her and convinced her she can’t make it in the wider world. As this latest novel begins, Holly is mourning Charlotte’s death from covid while grappling with the knowledge that her mother was abusive, particularly after discovering an inheritance that was concealed from Holly. Most human beings can understand complex feelings about someone they love while understanding that they hurt them, but it’s particularly salient for autistic people, who naturally gravitate toward figures they believe they can trust. King depicts the experience poignantly and realistically, and it makes Holly feel like a real autistic person in ways that having her exhibit symptoms gleaned from a Google search wouldn’t.

King has a checkered history with writing about disability, as is perhaps natural for someone who started his career in an era when we understood the subject far differently than we do today. Two of his earlier portrayals of developmental disability demonstrate the problems both he and genre fiction have historically had with writing such characters.

In King’s epic “The Stand” (1978), Tom Cullen, one of a coalition of survivors of a global pandemic, is clearly written as developmentally disabled in some way, although both his small-town roots and the time in which the book was written limit the specifics offered about what was then called “slow.”

Cullen is a gentle giant in the tradition of Lennie Small in “Of Mice and Men,” and anticipates genre characters like Hodor in George R.R. Martin’s “A Song of Ice and Fire” or John Coffey in King’s own “The Green Mile.” He has a catchphrase of sorts, habitually spelling out “moon” and declaring that the word relates to his current circumstances.

King’s depiction of Cullen isn’t malicious or deliberately insulting, but it’s not particularly empathetic either. At one point, the character is hypnotized, revealing a buried “God’s Tom” persona that is both intelligent and psychic. His disability only extends to the point when it’s more convenient to the plot for him not to be.

This subtext is made even worse in King’s “Dreamcatcher” (2001), a work of body horror written while King was recovering from a near-fatal car accident. The book and the movie adapted from it are probably most notorious for the central conceit – alien parasites that enter humans through their anal cavities – but one of its central characters, Doug “Duddits” Cavell, is a man with Down syndrome who is either psychic or an alien himself (it’s a very confusing book).

I bring this up not to bash King’s older writing but instead to illustrate how much his depiction of disability has evolved with Holly. Not only does her autism manifest itself in far more realistic ways, she’s a fully realized human being in ways that neurodivergent fictional characters seldom are. The Holly of this new novel is one with several books’ worth of character development behind her, and it feels genuinely cathartic to read the character at a stage in her life when she knows her own value and has a robust network of friends and partners.

Holly’s antagonists in the novel are a particularly chilling pair of King creations, elderly married college professors Roddy and Emily Harris, who have spent years snatching unfortunates out of a local park and cannibalizing them, bound to crackpot theories that consuming other humans will stave off their physical and mental degeneration.

The two make excellent foils for Holly, a woman who has come to accept that she works differently than most people, even if that’s not always to her advantage. In one of the novel’s most satisfying exchanges, Holly informs a furious Roddy that any benefit he believes he’s deriving from his ghastly fare is simply the placebo effect.

Holly was created around the time of a broader sea change in depictions of autism in fiction and, coincidentally, the removal of Asperger’s syndrome as a separate diagnosis from the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders in 2013.

The early 2010s saw characters like Abed Nadir (Danny Pudi), the fourth-wall-breaking fan favorite on NBC’s metatextual sitcom “Community,” and Saga Norén (Sofia Helin), the detective protagonist of the crime series “The Bridge.” Both of these characters are, like Holly, clearly written as autistic even though they aren’t explicitly described that way. Perhaps as a result, neither of them feels like a socially-responsible PSA about autism in lieu of a three-dimensional character, and neither does Holly in any of her appearances.

“Holly” isn’t a perfect book – Holly doesn’t care for profanity, and there’s a limit to how many times one can read the word “poopy” in third-person-limited narration. But it demonstrates that one of the last true rock stars of fiction can continue to grow as a writer, and doesn’t define success solely as a continuation of what’s worked for him before. That, his protagonist herself would say, gives me “Holly hope.”

Zack Budryk is an autistic journalist who covers environmental and energy issues for The Hill. He also co-hosts Stim4Stim, a relationship podcast by and for autistic people.