Battlestar Galactica Battlestar Galactica

Battlestar Galactica
9 pm/ET SCI FI
While many shows lose their viewership and often get yanked off the air without the benefit of a scripted finale, there are a few that retain their audiences until they get to say a proper good-bye to their fans. Closure is nice, but this is frakking Battlestar Galactica we're talking about! The bell tolls for the series after four seasons with a two-hour episode, in which Adama and Co. launch a desperate recovery mission for Hera. Keep the tissues handy. —Michael Chant

Friday Night Lights
9 pm/ET NBC
Now that Tyra's renewed interest in bad boys has blown up in her face, she decides it's time to play nice with Landry once again. But Landry doesn't exactly welcome her back with open arms, and it's up to Tyra to prove she can be a "giver" and not just a "taker." Elsewhere, Buddy blindsides Lyla when he comes clean about problems he's having. But that surprise is nothing compared to the shocking discovery Eric makes in tonight's episode. —Brie Hearn

Terminator: The Sarah Connor Chronicles
8 pm/ET FOX
Normally, it's what you did in your past that affects your future, but that line of reasoning gets tossed out the window when people and machines habitually visit the past to change the outcome of a war that hasn't happened yet. Jesse's submarine ride in the future spells trouble for Sarah, John and Derek in the present while Cameron's future (also in the present) hangs in the balance. —Michael Chant

Dog Whisperer
9 pm/ET National Geographic
Young and the Restless star Eileen Davidson calls upon Cesar Milan to help rehabilitate her nippy wheaten terrier, who has a habit of biting her son and frightening away all of his friends. Later, the dog guru helps a Jack Russell terrier named Elvis who gets all shook up when his owner runs the garbage disposal. —Karen Andzejewicz

Party Down
10:30 pm/ET Starz
A promising new entry in cable sitcomville has quite the impressive pedigree. One of the creators-executive producers-writers is Rob Thomas, who was the main man behind Veronica Mars. This new series chronicles the workaday misadventures of a crew of employees at an L.A.-based catering company called Party Down, where all the workers are showbiz wannabes. Among the regulars are former Mars-tians Ryan Hansen and Ken Marino, while Veronica's TV dad, Enrico Colantoni, guest stars on the premiere. Ms. Mars herself, Kristen Bell, is slated to appear on an upcoming episode. —Ray Stackhouse