Television critic Mike Hughes recommends two shows you might not want to miss tonight.

"CASTLE," 9:02 P.M., ABC

Amid TV's no-nonsense cops, we're getting some variety: This show joins "The Mentalist," "Bones" and others; the crimesolvers are as interesting as their cases.

Det. Kate Beckett is smart, serious and diligent. Richard Castle is merely smart; he's a crime novelist who needs to create a new character.

That's when someone starts copying murders from his books. Suddenly, these two opposites must work together. Nathan Fillion and Stana Katic are perfect and two real-life crime novelists -- James Patterson and Stephen Cannell -- briefly play themselves.

"DANCING WITH THE STARS" OPENER, 7 P.M., ABC

This edition has couples dancing with or against each other.

Chuck Wicks -- the likable new country star ("Stealing Cinderella") -- is lucky. His professional partner is also his girlfriend (and fellow country singer) Julianne Hough.

By comparison, a husband and wife compete. Jewel, the pop-turned-country star, and Ty Murray, the rodeo champ, have separate partners.

Also competing are professional dancers who are engaged to each other, Maxsim Chmerkovskiy and Katrina Smirnoff. He's with actress Denise Richards; she's with computer mogul Steve Wozniak.

Then there's Derek Hough, Julianne's brother. He's the professional dancer with singer Lil' Kim.

Derek is the show's current champion. The field also includes a previous winner (Mark Ballas, dancing with tiny gymnast Shawn Johnson) and two-time winner Cheryl Burke, with actor Giles Marini. Other celebrities: singer Belinda Carlisle, stuntman Steve-O, TV host Nancy O'Dell and former football star Lawrence Taylor.

OF NOTE

• "The Wonder Pets Join the Circus," 8 p.m., Nickelodeon. The pleasantly adequate "Wonder Pets" show is usually confined to 10 a.m. weekdays. Here's a primetime excursion (airing in Hawaii at 5 p.m.), in which the pets try circus acts. Pre-schoolers will be charmed; their parents will be undisturbed.

• "Battles BC" debut, 6 p.m., History Channel. This series links intelligent military historians and a powerful computer-graphic style, the sort used in the movie "300." The opener looks at Hannibal, whose battlefield brilliance once killed 70,000 Roman soldiers in a day, in an area barely twice the size of Central Park. Coming are hours on David, Caesar, Alexander and Joshua.

• House," 7 p.m., Fox. A book editor suddenly starts speaking frankly and insulting everyone. Dr. House -- who does that even when he's healthy -- searches for an explanation.

• "The Big Bang Theory," 7 p.m., CBS. On a plane ride to San Francisco, the guys are excited to spot Summer Glau, one of the "Terminator: Sarah Connor Chronicles" stars.

• "How I Met Your Mother," 7:30 p.m., CBS. Laura Prepon ("That '70s Show") plays Ted's pompous girlfriend from his college days.

• "Heroes," 8 p.m., NBC. Sylar finally finds his father (played by the talented John Glover), with unexpected results.

• "Rules of Engagement," 8:31 p.m., CBS. After mistreating his female assistants, Russell is required to hire a man. He soon takes advantage of that, in an episode that is both silly and funny.

• "Saving Grace," 7 p.m., TNT. Counterfeit pills became deadly at a teen party. That leads to a moving hour that juxtaposes Grace's new partner and the link between Grace's guardian angel and a condemned criminal.

• "Ax Men," 7 p.m., History Channel. The season's second hour focuses on human elements, including a California newcomer dismissed as a "pretty boy" by fellow loggers.