TONIGHT'S MUST-SEE

"House," 8 p.m., Fox. After a long rest for the start of "American Idol," this terrific show is back and strong. The case involves a savant pianist, played with subtle perfection by musician Dave Matthews. That's overshadowed by another mystery: Why is Dr. House secretly dealing with a Boston hospital? The answer offers a disturbing insight into this complex character. Leading to that is a terrific scene between House and Dr. Cameron (Jennifer Morrison).

"Pussycat Dolls Presents: The Search for The Next Doll" debut, 7 p.m., CW (digital cable channel 93). The CW people have figured out how to make an entertaining reality show. Like the latest, "America's Next Top Model," this show has a fine blend of contestants. Available is one spot in the pop group the Pussycat Dolls. That requires a zesty combination of singing, dancing and charisma. Complicating things is a flu that streaks through the prospects. The notion of holding the final tryouts in the midst of an outbreak seems contrived but interesting.

OF NOTE

"The Barbarians II: The Saxons," 6 p.m., History Channel. England was a chaotic collection of warring areas until key leaders emerged.

"Gilmore Girls," 6 p.m., CW (digital cable channel 93). Three generations head on a road trip when Lorelai goes to a North Carolina wedding with her mom and daughter. Don't expect it all to be cheery; Rory just had a fight with Luke, and Emily's tired of the demands from her ill husband.

"American Idol," 7 p.m., Fox. This is the week when the show trims to its dozen finalists. Tonight, the eight guys — who have had a bad week and a so-so week — get their chance to do better.

"NCIS," 7 p.m., CBS. Someone dug up the body of a missing Marine and put it on a chair in a house.

"Dirt," 8 p.m., FX. Lucy decides the magazine staff really needs some fun. So she's preparing a sex-themed issue.

"Law & Order: Special Victims Unit," 9 p.m., NBC. Stabler and Beck work an unsettling case involving foster children. That nudges Beck toward a decision.