Late in an early episode of Castle Rock, the show chooses a humorless moment to poke a little fun at the audience. Henry Deaver (Andre Holland) sits in halting conversation with a mysterious young man (Bill Skarsgård), their bodies separated by glass and their voices joined by jailhouse phones. Or Deaver's voice, at least—the young man opposite him has whispered only a few words since first being freed from captivity underneath Shawshank Prison, and is utterly silent now. Deaver, an attorney, outlines what he imagines their legal strategy to be; "You understand?" he finishes.

For a beat, the young man stares at him, all eyes and hair and cheekbones. Then speaks, his voice creaking with disuse: "Has it begun?"

One question, three meanings. For Deaver, it’s literal. For the viewer, who has by now heard and seen some … things about the young man, it takes on an unsettling gleam of ominous prophecy. But for the writers of Castle Rock, who have created a Hulu original series by essentially feeding Stephen King's literary catalog into a neural network, it’s a winking acknowledgment that preamble is done. After three episodes of scene-setting, of lore-building and creep-crafting, they’re saying, shit is about to pop off.

There’s yet another meaning to the question, though—one that only comes into focus if you take a big step back from the TV. Because the young man's question isn't simply applicable to Castle Rock, the first three episodes of which become available today. It’s applicable to a bigger movement within TV at large, and streaming services specifically. Netflix's pronounced push into science fiction with shows like Black Mirror and Altered Carbon has resulted in a now-common sight: its competitors following suit. Castle Rock, it seems, is only the first King-sized salvo, and over the next year or so it'll be followed by an unprecedented parade of genre fare from Hulu, Amazon, and YouTube.

Genre television is not a new idea for streaming platforms. One of Amazon's first forays into hourlong drama was an adaptation of Philip K. Dick's novel The Man in the High Castle, and The Handmaid’s Tale helped make Hulu a prestige player. (Even before that, Hulu had made its way into original series with shows like supernatural comedy Deadbeat.) But genre—and especially sci-fi—has proven to be specially suited to streaming audiences. It's story-driven; it's often pulpy, with that pulp stringing viewers from one episode to the next; it's less prone to I Have Important Insights About the Human Condition-style navel-gazing that can infect showrunners and bog down shows. And last week’s Comic-Con International proved the perfect opportunity for streaming services to tease their efforts.

Hulu threw all its might behind Castle Rock, and for good reason: while the service is reportedly developing numerous genre series, including ones based on Anne Rice's Vampire Chronicles and the comic book Postal, the Stephen King-inspired series is a) done and b) judging from the first four episodes, at least, good. The fictional Maine town it's named after is well-known to King fans (it serves as backdrop for Cujo, Needful Things, and novella "The Body," among others), and here it's given flesh, albeit desiccated flesh, as a blighted depression town with little to offer beyond opioid addiction and secrets. Deaver, a Castle Rock native, has returned after years away, only to discover that its denizens—from childhood friend Molly Strand (Melanie Lynskey, carrying a fine-tuned fragility) to the recently deceased prison warden (Terry O'Quinn) to Skarsgård's gaunt, feral mystery prisoner—carry secrets of their own.

As Deaver, Holland exudes a weary impatience that provides perfect counterweight to the macabre weirdness of the surroundings, especially as that weirdness takes on context. Despite having J.J. Abrams as executive producer, this is not a show of mystery boxes. There are boxes in Castle Rock, yes, but they're opened almost immediately, even if not everything inside is illuminated. "Stephen King doesn't really write mystery box novels," said co-creator Sam Shaw at the show's Comic-Con panel. "We tried to chart a course that in some ways is driven by some mysteries … and then also to answer some questions, perhaps earlier than the audience expects."

YouTube, for its part, has plenty of mystery built into its scripted efforts—like, for example, why it spent more than two years assuming people would pay a monthly subscription for "shows" from PewDiePie and other platform-grown stars. That was YouTube Red, though; after a timely pivot earlier this year, the Google-owned company has rebranded its paid plan as YouTube Premium. It lived up to its name almost immediately, quietly introducing a new series, Impulse, that represented director Doug Liman's foray back into the world of his 2008 sci-fi film Jumper. While that description may not inspire confidence, the result does: an assured, teen-centered series that grapples with sexual assault without losing its sense of adventure. It's little wonder, then, that Liman and crew came at Comic-Con to goose the already positive word of mouth, even announcing the show's renewal for a second season.

Impulse isn't YouTube's only genre play; later this year the platform premiers Origin, a deep-space thriller that looks to combine the we're-all-screwed sci-fi fun of the unjustly maligned Cloverfield Paradox with the character-driven mystery of Lost. The premise is simple: After signing on for an all-expenses-paid journey to another planet, a group of Earth’s first would-be colonizers wake up on a spaceship to find they've been abandoned. All the other passengers and crew? Gone. Well, mostly. A 12-minute sequence shown at the series' Comic-Con panel had its bumps, but director Paul W.S. Anderson (Event Horizon, AVP: Alien vs. Predator, the inexplicably long-running Resident Evil franchise) has a practiced touch with dark, dank spaces, and the setpiece's climax delivered just enough grotesquerie to sell the promise.

Neither Hulu nor YouTube can keep pace with Amazon Studios, though. At a well-attended panel, the company assembled creators of six of its current and upcoming genre shows: spy tale Tom Clancy's Jack Ryan (Carlton Cuse of Lost, Bates Motel, and Colony); psychological thriller podcast adaptation Homecoming (Mr. Robot creator Sam Esmail); new seasons of The Tick (Ben Edlund) and horror podcast adaptation Lore (everything ever's Gale Anne Hurd); beloved sci-fi series The Expanse, newly rescued off the slag heap at Syfy after three seasons; and Neil Gaiman's Good Omens, based on his and Terry Pratchett's 1990 fantasy-comedy novel. While not much footage was shown—a snippet here, a BTS featurette there—Amazon’s intent was clear. Yes, Transparent and The Fabulous Mrs. Maisel are great, but if you don’t feel like laughing or crying, we’ve got stuff for that too.

And that’s just the series close to completion. Amazon's development slate includes adaptations of numerous sci-fi books and book series (Iain M. Banks' Culture series, Larry Niven's Discworld saga, and Neal Stephenson's Snow Crash), as well as an episodic update of Galaxy Quest, Greg Rucka's near-future comic book Lazarus, and Black America, an alternate history in which freed slaves received reparations and formed a sovereign nation in the American South.

It should still be said: None this may make a dent in Netflix's current reign. The company’s massive development slate has already resulted in Black Mirror, Altered Carbon, Stranger Things, Lost in Space, Sense8, 3%, Dark, and more. (Even if some of those were doomed from the outset.) But every platform has evolved the same way—starting small, adding comedies, pursuing awards (not so fast, YouTube), and then settling into a something-for-everyone groove—and that last bit wouldn’t be possible without genre TV, the sustainable, slow-burn programming that's as likely to be a watercooler sensation as it is to be a word-of-mouth creeper niche hit. And after years in the desert, caught between basic-cable budgets and high-concept disappointments, it's nice to have some change on the horizon. Has it begun? Oh, it's begun.

More Great WIRED Stories

• How Google's Safe Browsing led to a more secure web
• PHOTO ESSAY: The most exquisite pigeons you'll ever see
• Scientists found 12 new moons around Jupiter. Here's how
• How Americans wound up on Twitter's list of Russian bots
• Beyond Elon's drama, Tesla's cars are thrilling drivers
• Get even more of our inside scoops with our weekly Backchannel newsletter