(CNN)More than any other network, Fox seems to be working backward this season -- coming up with marketing campaigns, then figuring out its shows fit into them. That kicks off this week with premieres of "Lethal Weapon" and "The Exorcist," two series derived from familiar movies.
'Lethal Weapon,' 'Exorcist' Fox series try to scare up TV ratings
Having already spawned a quartet of films from 1987 to 1998, "Lethal Weapon" lends itself more to making the leap, and hasn't tinkered much with the existing formula. By contrast, "The Exorcist" was essentially a title in search of a show, and it's still not entirely clear what to expect beyond the spooky but somewhat messy and scattered pilot.
"Lethal Weapon" casts Clayne Crawford ("Rectify") in the role of Martin Riggs, the cop who suffered a devastating personal loss and now acts like he wants to die, allowing him to chase bad guys with utterly reckless abandon. He's paired with Roger Murtaugh (Damon Wayans), a family man who has already experienced a brush with his mortality and isn't eager to have another. So much for coasting toward retirement.
For these purposes, casting was half the battle, and there's a nice rapport between the two leads. That said, there's nothing particularly distinctive about the show -- including the ample action and shootouts -- and it risks quickly blending into the roster of buddy-cop dramas that Fox has trotted out with numbing regularity over the last few years.
"The Exorcist" faces a thornier challenge, and tries tackling it with slightly more ambition and style, but less clarity.
Billed as being "inspired by" William Peter Blatty's book, the premiere throws in a specific if rather subtle nod to the 1973 adaptation, which scared the bejesus out of moviegoers nearly two generations ago.
Here, the focus is on two priests and one unlucky family. Young Father Tomas (Alfonso Herrera) is approached by Angela Rance (Geena Davis), a parishioner who fears there's a demonic force in her home-- an unseen force that's also plaguing her daughter.
"There are things going on in the house," she says ominously.
Meanwhile, Father Tomas experiences visions of an exorcism in Mexico, which eventually causes him to seek out the world-weary Father Marcus Keane (Ben Daniels), the kind of priest who isn't above pulling a gun on a colleague dispatched by the Vatican.
The hour builds toward bringing the two priests together -- young skeptic and grizzled veteran of exorcisms past -- to find out what's happening around the Rance house. But aside from the walks down eerie hallways and the occasional jump-out-at-you scares, it all feels difficult to sustain on an episodic basis.
In another throwback, "The Exorcist" will air Fridays, where the network found a receptive audience for horror years ago with "The X-Files," which recently made its own comeback.
Fox isn't the only network relying on such known commodities this season, but it is employing that formula the most relentlessly. The titles should spur a measure of curiosity, which for new series can be half the battle.
From that perspective, there's no mystery as to why Fox executives ordered these shows. As for whether the producers can keep these well-known stories fresh enough to retain an audience, the Devil really is in the details.
"Lethal Weapon" premieres September 21 at 8 p.m. "The Exorcist" premieres Sept. 23 at 9 p.m.