Fringe Fringe

9/8c Fox
February's mid-season cliffhanger was a real mindblower when an astounded Olivia saw that Peter shared the same glimmer with objects and people from the alternate universe. Needless to say, she's not too thrilled with Walter's deception, but wait until you find out how he did it. Flashing back to 1985 — take note of the hair, music and graphics — Walter does his best to explain why he did what he did, and what it means for the future. Oh, and we also find out why Nina Sharp needed that prosthetic hand. — Joe Friedrich

Vampire Diaries
8/7c CW
Elena and Stefan go on an awkward double date with Caroline and Matt. Of course, Elena and Matt used to be an item, but Stefan's arrival pretty much put a stake in that relationship ever being rekindled. And insecure Caroline, obviously, believes Matt still has eyes for Elena. Which, of course, he does. As for the whiskey-soaked Damon, who still isn't over the fact that his beloved Katherine couldn't care less if he's alive or undead, gets a shock when Anna brings a surprising guest to visit him. — Tim Holland

Private Practice
10:01/9:01c ABC
The big news is the arrival of Derek Shepherd's little sister, Amelia (Caterina Scorsone). She's a surgeon, too, and she's a junior member of the team treating Kayla, the comatose surrogate being kept alive until the triplets she's carrying become viable. Kayla showed signs of life as last week's episode ended, and Amelia thinks she can save her. But her boss (Nora Dunn) doesn't; nor does Addison. Meanwhile, tonight's Cooper-Charlotte bickering backdrop is a sex-education seminar for seniors. — Paul Droesch

The Mentalist
9/8c CBS
The team meets their new boss, Madeleine Hightower, played by Aunjanue Ellis. That can be a tense situation for anyone, but probably even more so for Lisbon, who spends a lot of time acting as a buffer between Jane and any new acquaintances. The man can read people with amazing skill, but talking to them tactfully isn't his greatest gift. The team also investigates a murder that turns into a search for a priceless ring stolen from a British museum. — Bill Ecklund

Project Runway
10/9c Lifetime
It wasn't Kors lite last week. The designers created their own digitally printed fabric patterns, but this computer wizardry didn't always click with the judges. There sat arbiter Michael Kors, whose comical critique is always worth a laugh. Among his clothes cracks last week: "It looks like a dirty tablecloth." "The poor model looked like she was walking in a striped tepee." "It's like a disco straitjacket." Another man with comedy flair, contestant Anthony Williams, got the boot last week, so the contest advances without his rich entertainment value tonight. In this outing, the designers craft looks for a celebrity known for being headstrong. — Dean Maurer