Friday's TV Highlights: Fox airs the season finale of 'Dollhouse'
THE END: Echo and Sierra (Eliza Dushku, left, and Dichen Lachman) reunite in the series finale of "Dollhouse," at 8 p.m. on Fox.
DogTown: A terrier mix tests a woman's patience with hyperactive behavior, while a man tries to make a Catahoula leopard dog mix more adoptable by helping her overcome her fears (5 and 8 p.m. National Geographic).
Smallville: Oliver's past comes back to haunt him when his former teacher, the Dark Archer, seeks revenge by taking aim at Chloe and Lois, in this new episode (8 p.m. KTLA).
Medium: Allison (Patricia Arquette) dreams of a schizophrenic child, whom she later meets as the seemingly well-adjusted roommate (Danielle Panabaker) of a missing psychiatric patient in this new episode (9 p.m. CBS).
Shark Tank: A California entrepreneur wants to bring back old-fashioned ice cream men in this new episode that also features an update on the sharks' venture with an Arizona woman and her unique plush toys (9 p.m. ABC).
Kitchen Nightmares: Chef Gordon Ramsay returns for this new season of the series that visits eateries that have fallen on hard times and explains (explicitly and in great detail) to their owners how to turn them around, on the season premiere (9 p.m. Fox).
Bill Moyers Journal: AFL-CIO President Richard Trumka is calling on America's workers to stand up and fight (9 p.m. KCET).
I Shouldn't Be Alive: A young man is attacked by a grizzly bear after striking out on his own while hunting with his father (9 p.m. Animal Planet).
Numb3rs: The team searches for a serial killer who targets men who solicit prostitutes in this new episode (10 p.m. CBS).
20/20: Andrew Young, former aide to Sen. John Edwards, discusses his upcoming memoir (10 p.m. ABC).
Spartacus: Blood and Sand: Spartacus becomes enslaved in gladiator school, and his desire for vengeance must be suppressed (10 p.m. Starz).
London Live: Lady Gaga performs in London; songs include "Paparazzi" and "Poker Face" (11 p.m. VH1).
Back to the Future: The Next Global Crisis: Maria Bartiromo moderates a debate on the choices that must be made to protect the global economy in this new special (7 p.m. CNBC).
Miss America: Behind the Curtain: Clinton Kelly hosts a view of preparations for the pageant (10 p.m. TLC).
Black Hawk Down: Directed by Ridley Scott, this fact-based 2001 drama graphically shows what happened when U.S. soldiers were dropped deep in Somalia in 1993 to retrieve human targets. Tom Sizemore, Josh Hartnett, Ewan McGregor, Eric Bana and Orlando Bloom star (7:35 p.m. Starz).
Winter X Games: From Aspen, Colo. (9 a.m. ESPN2 and 4 p.m. ESPN).
Pro basketball: The Lakers visit the Philadelphia 76ers (4 p.m. KCAL); the Clippers visit the Minnesota Timberwolves (5 p.m. FS Prime).
Track and field: Millrose Games (5 p.m. ESPN2).
Tennis: Australian Open, Women's Final (12:30 a.m. ESPN2).
Photo: Richard Foreman / Fox