For the first half-hour of its first episode, Showtime’s “The Affair” is a well-made, if slightly predictable domestic drama. We meet Noah Solloway (Dominic West), a brownstone-dwelling writer with a lovely wife (Maura Tierney), four rambunctious children, and chiseled good looks. “My life was pretty fucking perfect,” he tells us in Sunday’s premiere, and even as we see Noah’s frustrations—his wealthy, underminey father-in-law; his inability to have sex without being interrupted by those pesky kids—we have little reason to doubt him. He loves his wife! He’s just published his first novel! But the show is called “The Affair,” and so when, en route to his father-in-law’s east Hampton mansion for the summer, Noah meets a flirtatious waitress with piercing eyes, (“Luther”’s Ruth Wilson), we know what to expect: temptation, infidelity, a heavy dose of guilt. 

Around the 30-minute mark, though, the episode abruptly takes a turn. Noah’s perspective disappears, and suddenly this story belongs to Alison Lockhart, the Montauk waitress played by Wilson. Alison is also married, to a loving, volatile rancher named Cole (Joshua Jackson—a casting choice that should bring joy to the heart of former teenage girls everywhere), and the couple are wrecked with grief after losing a child. 

What gives the show both its novelty and its thrill is the framing device: Noah and Alison are both narrating these events, or their version of it, to a detective in a police interrogation room some time later. Imagine “True Detective,” if that series was concerned with intimacy and relationships instead of Nietzschean grandstanding. Or “Gone Girl,” minus the sociopaths.

And unlike “True Detective,” where the narrators were unreliable but the camera remained trustworthy, subjectivity is threaded into every step of the filmmaking in “The Affair.” In the episode’s second half, we don’t just see the same events from Alison’s vantage point; we see how Alison’s and Noah’s memories diverge. At the diner where Noah eats with his family, Alison’s skirt is longer, her dress buttoned up higher, her hair tied back. His clothes are slimmer, more expensive. (There’s an interesting undercurrent of class tension in the episode that I hope remains an ongoing theme.) Instead of flirtatiously touching his arm, she’s withdrawn, as though anxious that the sight of this still-whole family might prick her. When they run into each other later on a beach, her flimsy sundress has been replaced by sensible shorts and top, with a protective blanket wrapped around. Wilson, one of England’s best and most versatile young actresses, gives an astonishing performance, essentially playing two characters: one coy and knowing, the other wan and depressed, her self-loathing practically oozing out of her skin.

This isn’t the first television show to do the “Rashomon” thing, of course. The device has been used in countless sitcom and cartoon episodes as a gimmicky change of pace, from “All in the Family” to “Spongebob Squarepants.” But “The Affair” fully commits, without promising any definite answers. The first episode leaves us with a mystery—what crime or accident is being investigated?—but gives us other questions that seem more vital. Are Alison and Noah lying? Are they lying to themselves? Who gets closer to the truth? Everyone wants to be the hero of their own story, and these clashing narratives are subtle enough to suggest the vagaries of memory without implying subterfuge. It’s hard to tell where the creators, Sarah Treem and Hagai Levi (previously of “In Treatment”), will take the show from here. (Showtime only made one episode available to critics.) But this warm, sexy character drama, laced with dread, is certainly one of the most promising new shows of the fall.