(CNN)Time travel is among this TV season's mini-trends. But there's a big difference between tinkering with the past or future once and getting away with it -- as in a movie like "The Terminator" -- and making a weekly habit of it.
'Timeless,' 'Frequency' may not have time on their side
Two reasonably interesting new series explore the topic premiering the same week: NBC's "Timeless" and CW's "Frequency." The latter network's "The Flash" also continues to muck around in what-if and alternate-universe scenarios in its third-season debut, offering further evidence of how tricky this territory is to navigate.
"Timeless" is perhaps the most direct contemplation of what's known as "the butterfly effect," in which messing with time can have unforeseen consequences, large and small.
Perhaps appropriately, the NBC drama dips into the way-back machine, recalling everything from the 1960s series "The Time Tunnel" to the movies "Timecop" and "Terminator" -- both of which, incidentally, became short-lived TV shows.
Here, time travel becomes a kind of procedural, with a crack team dispatched into the past each week to thwart attempts to alter history. The trio consists of a history professor, Lucy ("Rectify's" Abigail Spencer); special-forces officer, Wyatt (Matt Lanter), the muscle to Lucy's brains; and time-machine operator/pilot, Rufus (Malcolm Barrett).
Rufus happens to be black, which provides the foundation for what little social commentary and humor the show musters (he uses fake names like "Denzel Washington"), given how he's treated and eyed in earlier periods. In the premiere, it's the 1930s, as they endeavor to stop a nefarious time traveler ("ER's" Goran Visnjic) who stole the mate to their capsule from interfering with the Hindenburg explosion. The second hour involves the assassination of Abraham Lincoln.
"Timeless" has the potential to be fun in a simple-minded sort of way, so long as you don't fret about the premise's implications, which risk going from zero to ridiculous in a matter of seconds. It also has a deeper mythology regarding the bad guy's shadowy motivations and ripple effects on Lucy's personal life, but those elements are likely going to require considerable patience, "The Blacklist"-style, before shedding much light on them.
If "Timeless" provides the macro view of toying with timelines, "Frequency" -- adapted from the 2000 movie that starred Dennis Quaid and Jim Caviezel -- represents the micro version.
The series makes a gender switch, casting Peyton List as Raimy Sullivan, a detective who stumbles into ham-radio contact with her long-dead father (Riley Smith), an undercover cop who met an untimely end.
After working to save him, they're left to try sorting out a mystery while separated by 20 years, complicated by the potential fallout from Raimy upsetting history.
There's some symmetry there with CW's most popular show, "The Flash," which closed last season with the superhero speeding back to save his murdered mother, with all the ripples that entails. While the show largely got away with its alternate-Earth scenario in Season 2, if the premiere is any guide, the writers are skating -- or racing -- along a very thin edge.
"The Flash" has demonstrated that it's possible to keep an audience engaged with time-travel stories, but also the narrative pitfalls associated with such plot lines on an episodic basis.
While "Timeless" and "Frequency" are good enough at the outset to merit second looks, based on the history of programs being able to sustain that delicate balancing act, it doesn't feel like time is on their side.
"Timeless" premieres October 3 at 10 p.m. on NBC. "Frequency" premieres October 5 at 9 p.m. and "The Flash" premieres October 4 at 8 p.m. on CW.