Christy, the CBS series that exhibits a high level of faith rarely seen on network television, is returning as a midseason replacement, and the future of the show could hinge on a two-hour special episode to be aired Thanksgiving night.

The series opened last Easter as the top-rated CBS show for the week, but Nielsen ratings dipped for the remaining five weeks of a trial run. Still, the network ordered 13 more episodes for the current season. CBS president Jeff Sagansky was the show's biggest booster in putting it on the schedule last season.

But Sagansky has become a Sony executive, and Christy faces many hurdles before becoming a regular television fixture.

Advertising pays the bills, and ratings are the bottom line. A Christy episode costs $1.2 million to shoot, which is $300,000 more than the ad-rates revenue generates. (Some of the deficit may be whittled down via video sales.) The series is expensive to produce primarily because of the on-location shooting and the 35-millimeter cinematic process, used in motion pictures, but rarely in episodic television. In addition, Christy's demographics last season were poorest among urban viewers and those ages 18 to 35, the viewers advertisers covet most.

CBS, although finishing first in the Nielsen ratings last season, has languished in third place at the beginning of the fall season. Executives are not likely to be overly patient waiting for a show to build an audience.

Yet there are signs of hope.

Washington Post television critic Tom Shales says that because "CBS is experiencing a multitude of failures now," Christy will very likely be on the air soon. "The network got lots of praise for putting on a wholesome show with religious themes," Shales says. According to executive producer ...