“Treehouse Of Horror XX” 8 tonight, Fox

It has been a Halloween tradition for 20 years and, for once, it actually airs before Halloween. “The Simpsons” present another set of frightening — and funny — tales, including one that has news anchor Kent Brockman transforming into an enraged zombie after devouring one of Krusty’s fast-food sandwiches. Other stories see Lisa channeling Alfred Hitchcock and tavern-owner Moe serving up drinks flavored with Homer’s blood. Mmmm, blood beer.

“Mad Men” 10 tonight, AMC

The marvelous third season of “Mad Men” continues as Peggy and Paul compete for an account. Our money is on Peggy.

“Trauma” 9 p.m. Monday, NBC

On “Trauma,” we’ve got yet another explosion. This time, it’s at a Chinese restaurant in San Francisco. We envision moo goo gai pan everywhere.

“NCIS” 8 p.m. Tuesday, CBS

Apparently, practical jokes tick some people off. On “NCIS,” the team investigates a Halloween murder that may be tied to revenge for a humiliating prank.

“Modern Family” 9 p.m. Wednesday, ABC

We usually dread the first day of school. But on “Modern Family,” prime time’s best new sitcom, it’s sure to be packed with laugh-inducing moments.

“Glee” 9 p.m. Wednesday, Fox

Why are we smiling? Because “Glee” is on tonight, and the “cool kids” at McKinley High School are about to get a taste of their own medicine.

“FlashForward” 8 p.m. Thursday, ABC

With all its visions into the future, twisty mysteries and juicy intrigue, “FlashForward” continues to blow our minds. Now pass the aspirin, please.

“The Office” 9 p.m. Thursday, NBC

On “The Office,” Jim and Pam return from their blissful honeymoon only to be shocked when they hear about who Michael has been dating.

“White Collar” 10 p.m. Friday, USA

In the new series, “White Collar,” an uptight FBI agent (Tim DeKay) and a slick con man (Matthew Bomer) form an unlikely crime-fighting partnership. Maybe the show will prove to be fresher than its premise.

“My Super Psycho Sweet 16” 10 p.m. Friday, MTV

Getting a jump on Halloween, “My Super Psycho Sweet 16” is a horror flick about a teen birthday bash that goes horribly awry. Seems that one of the party-crashers is a serial killer.

“Always and Forever” 9 p.m. Saturday, Hallmark

In the TV film “Always and Forever,” former high school sweethearts (Rena Sofer and Dean McDermott) reconnect at their 20-year high school reunion. Can love work the second time around?