The intriguing CW series “Frequency” starts out looking as if it were going to be a bittersweet, nostalgia-tinged time-travel drama in the Stephen King-”Twilight Zone” lineage, and that probably would have made for a comfortably satisfying show, the kind you can half-watch while doing something else. In the last third of the premiere, though, things take a joltingly different, more complicated path. Sorry, couch potatoes, but it looks as if you might have to keep both eyes on the screen for this one, which begins on Wednesday night.  Peyton List (“The Tomorrow People”) stars as Raimy Sullivan, a 28-year-old detective with policing in her blood. Her father, Frank (Riley Smith of “Nashville”), also a police officer, was killed 20 years earlier while working undercover. He ended up disgraced, because investigators concluded that he was involved in corruption, and Raimy has grown up hating him for that and for seeming to abandon his family.  That all changes when an old ham radio that Raimy and her father played with when she was a girl mysteriously crackles to life. The CW audience skews young enough that some viewers may need to pause at the first commercial break to Google “ham radio,” but it’s a sweet little conceit worthy of one of Mr. King’s novels. There’s even a pivotal baseball element — as there was in the 2000 movie that inspired this series — though it involves the Yankees, not Mr. King’s beloved Red Sox.  Anyway, 2016 Raimy and 1996 Frank soon realize that by using the radio, they can talk to each other across time. And Frank gives Raimy reason to rethink the conventional wisdom that he was a dirty cop.  Had the premise stopped there, “Frequency” would have made an appealing limited series, with Raimy spending, say, 10 episodes working with her father to clear his name and maybe even solve the serial-killer case that comes into play during the premiere. But Jeremy Carver, the creator of the series, knows something about how to string out a science-fiction idea from his long involvement with the bedrock CW hit “Supernatural.” The premiere takes a twist — as the film did — that sets up dizzying possibilities for where this series could go (or, of course, for how it could spin out of control and become too labyrinthine to bother following).  Ms. List is appealing in the lead role, and she’s surrounded by a solid supporting cast, including Daniel Bonjour as Raimy’s boyfriend, and Mekhi Phifer as Frank’s former partner, who is still on the force in 2016. Frank’s portion of the story, of course, also allows for dollops of the 1990s nostalgia so popular these days on TV, where viewers who were children back then are so coveted.  The manipulation of time and the perplexing theoretical problem of how altering past events affects the future have been science-fiction TV subjects forever, from the “No Time Like the Past” episode of “The Twilight Zone” to “The Time Tunnel” series of the mid-1960s, right up to NBC’s “Timeless,” which made its debut on Monday. It’s hard to make an impression in a genre so heavily worked, especially with a series drawn from a moderately popular movie, but “Frequency” is in good hands and has promising ingredients.  A version of this review appears in print on October 5, 2016, on page C5 of the New York edition with the headline: Daughter and Father, Radioing Across Time. Order Reprints| Today's Paper|Subscribe
At first this new series seems as if were going to be a mere time-jumping drama tinged with nostalgia, but it morphs into something more complex.