How I Met Your Mother

Photo: HOW I MET YOUR MOTHER: RON JAFFE

The quintet of stars on How I Met Your Mother has jelled into one of the most crackling, entertaining ensembles on television. A little like the castaways on that ABC hit, the characters reside on a mysterious island (Manhattan), and much of the entertainment comes from watching them in poignant, enlightening, and scary flashbacks. (Yes, scary. Did you catch Lily — a Kewpie-faced Alyson Hannigan — in her Elvira Goes to the Prom getup?) Mother poses a provocative question: Is there any joy in watching a series whose ending has already been spoiled? After all, last fall’s pilot episode pretty much nixed the idea that its key couple, Robin (Cobie Smulders — it should be Smolders, as she’s so ridiculously appealing and charismatic) and Ted (Josh Radnor, a Schwimmer-ian man with thatched dark hair and hound-dog eyes), would end up makin’ babies together.

For the most part, the time traveling has served Mother well. It provides a diverting sideshow to the present-day Ted and Robin gooeyness, which is hard to root for because we know it doesn’t end well. Particularly diverting: a February episode in which we saw how Barney (a terrific Neil Patrick Harris) transformed from a hippie who pronounced Nicaragua as if it were spelled with four r ‘s — the writers have a flair for mid-’90s politically correct nostalgia — into a catchphrase-coining womanizer.

Aside from tantalizing Angel fans (Amy Acker and Alexis Denisof, Hannigan’s real-life husband, appear), this week’s finale promises to spin the series in a new direction, which is just fine: Sometimes the destination is less important than the journey.