TODAY'S MIGHT-SEES

"Mad Men," 7 p.m., AMC. Only a week away from its season finale, this Emmy-winning drama has been throwing its characters into chaos. Don Draper has been restless ever since his wife threw him out. Last week, he took an underling's place on a Halloween trip — then spent most of the time on a tryst with someone half his age. Tonight he meets an old friend. Meanwhile, Pete has been wobbling lately. Tonight, that affects a major deal; also, Joan introduces her fiance.

"The Simpsons," 7:30 p.m., Fox. We're two weeks away from "Treehouse of Horror," an annual highlight. First, here's a 7:30 p.m. rerun of a previous one, with takeoffs of "E.T.," "Se7en" and "Mr. and Mrs. Smith." At 8 p.m. is a new episode, with Bart trading places with a rich kid who looks like him. At 10:30 p.m., a rerun has Marge and Lisa in ballet school.

OF NOTE

"True Blood," 6 p.m., HBO. There are joyous moments early, with Sookie the virgin and Bill the vampire. Then come the aftershock heightened by Sookie's addicted brother. It's another terrific episode.

"Entourage," 7 p.m., HBO. In a good episode, here's a major turning point for Ari. He sees no reason why a funeral can't be time to do business.

"Desperate Housewives," 8 p.m., ABC. Everyone seems jealous of Bree's business success. Lynette — a rising executive when this series started — offers unwanted advice.

"Masterpiece: The Last Enemy," 9 p.m., PBS. This five-week miniseries started with Stephen returning for his brother's funeral. By the end of the day, he was in love and in bed with Michael's widow, Yasmin. At the end of the second episode came another jolt — an apparent glimpse at Michael, alive. The complications keep building amid a government coverup. Stick with this intelligent (if disturbing) thriller.

"The Unit," 9 p.m., CBS. Undercover operations can be tricky. Mack pretends to be a boxer; Bob pretends to be a chemist — and is soon held hostage by drug dealers.