What's on TV Tonight | September 20

Up All Night 7:30-8pm, NBC. The cancellation of Ava's show puts a strain on her relationship with Reagan, while Chris decides to take the opportunity to go back to work.

The Office 8-8:30pm, NBC. A pair of new, young employees put David and Jim on the defensive.

Glee 8-9pm, FOX. In case you didn't get enough Britney Spears the first time around, New Directions is at it again as Brittany turns to the pop idol's music in the hopes that it will lift her spirits.

Parks and Recreation 8:30-9pm, NBC. Leslie heads to D.C. to visit Ben and lobby for Pawnee interests while Ron is put in charge of throwing the staff a barbecue in her absence.

Louie 9:30-10pm, FX. Will Louie get the Late Show job or will he get stabbed in the back, find out in the conclusion of three-part arc.