Summer Glau

In a somewhat surprising move, Fox has picked up "Terminator: The Sarah Connor Chronicles" for a full season.

The network has ordered the back nine episodes of the show’s second season from Warner Bros., sources say.

The sci-fi series has garnered a relatively modest rating on Monday nights this fall. Its most recent episode was seen by 5.7 million viewers, with a 2.3 adults 18-49 rating and a 6 share, tying NBC’s "Chuck" in the 8 p.m. time period.

Will get some clarity on this on Monday, but there’s a few reasons why Fox might have moved forward with an order.

The network recently ordered two scripts of the show, so perhaps the stories came in strong. Midseason sci-fi drama "Dollhouse" might be another factor — Fox’s previously announced winter schedule pairs "Dollhouse" and "24" on Mondays and "American Idol" and "Fringe" on Tuesdays, without "Terminator" listed. So perhaps the network has a new scheduling configuration in mind to support its sci-fi efforts.

Yet another potential factor is that "Dollhouse" has had some creative struggles. Sources say the newer scripts are stronger than the first batch, but if there’s any chance of the show being delayed Fox might have decided to keep "Terminator" in the mix.

One of the most likely reasons for a pickup, however, is simply that Fox executives like the show and the network’s overall viewership levels jet up after the first of the year powered by "American Idol." They likely believe the series has a chance to improve.