"The River" (8 p.m., ABC/Ch. 4) attempts one of the most difficult tasks in television - creating a horror story that's a continuing narrative from week to week.

There have been scary TV movies and miniseries. And scary anthologies, with a different cast and different story every week.

But last year's "American Horror Story" is an anomaly in that it pulled off a 12-episode horror story. Although, given that Season 2 will a a completely different story, you could argue that "AHS" was a miniseries.

"The River" is going to try to have it both ways - a serialized drama with stand-alone episodes.

As the series opens, popular TV adventure host Dr. Emmet Cole (Bruce Greenwood) has gone missing in the Amazon. His wife (Leslie Hope) and adult son (Joe Anderson) go looking for him, which doesn't seem like a good idea because there's something standing in their way.

Might be an evil spirit. Might be the smoke monster from "Lost," or something closely related to that.

And there are all kinds of jerky, indistinct camera shots - a cross between "The Blair Witch Promise" and one of those dumb ghost-hunter shows - that are supposed to scare us.

And there are some scares here. Along with an intriguing mystery.

But in the second episode (9 p.m., ABC/Ch. 4), we go away from the big mystery for a rather predictable side story. That's not as scary as it wants to be.

"The River" is very ambitious. Probably too ambitious.