Kellie Martin (“ER”) returns to the bookstore as the star of the “Mystery Woman” (8 p.m. today, Hallmark) sleuth series. She’s Samantha Kinsey, who has inherited a bookshop from her uncle. She also appears to have been endowed with vast resources, all the time in the world and limitless patience.

She runs the store, writes whodunits and, in her spare time, solves crimes on behalf of the hapless police and her best pal, Cassie (Nina Siemaszko), the local district attorney. Along the way, she’s aided by Philby (Clarence Williams III), a fellow bookworm with ties to the intelligence community.

Nobody checks into a Hallmark movie for edgy dramas or complex characters, but Samantha’s indefatigable cheerfulness is beyond belief. While other mystery franchises (“Monk,” for example) make the most of their characters’ idiosyncrasies, Kinsey remains placid to a fault. You’d like to see her get angry, or at least annoyed, just once. The only mystery to this woman is where she misplaced her personality.

¢ In other music news, select NBC stations will air an “Access Hollywood” (8 p.m. today, NBC) special about the Cirque Du Soleil production “Beatles Love,” showcasing the music of the Fab Four. The special includes interviews with surviving Beatles Paul McCartney and Ringo Starr, and Yoko Ono and Olivia Harrison.

¢ Imagine two 12-year-old boys posing the question: What’s more awesome, a karate chop or a boxer’s roundhouse punch? “Fight Science” (8 p.m. Sunday, National Geographic) uses computer graphics and a battery of experts to examine the physics and biology behind Asian martial arts and boxing.

Today’s highlights

¢ Scheduled on “48 Hours Mystery” (9 p.m., CBS): A Texas man dies under strange circumstances after surviving two murder attempts.

¢ A cry for help on “Crossing Jordan” (9 p.m., NBC).

Sunday’s highlights

¢ Grown-up celebrities including Jon Stewart, Megan Mullally, Tony Hawk, Cynthia Nixon, Taylor Hicks, Jewel and Nelly Furtado share embarrassing tales of adolescence on “Nick News with Linda Ellerbee: The Worst Years of My Life? Surviving Middle School” (7:30 p.m., Nickelodeon).