Just when did Mariel Hemingway become Chuck Norris? The actress, who as a teen was nominated for an Oscar for 1979’s “Manhattan” has grown up to become an action star. “First Shot” (7 p.m., Sunday) gives Hemingway her third chance to play Alex McGregor, a no-nonsense, shoot-from the hip Secret Service agent assigned to protect the president (Gregory Harrison).

When the first McGregor movie, “First Daughter,” aired in 1999 it became the most popular made-for-cable movie ever. In that film she saved the president’s daughter Jess Hayes (Jenna Leigh Green) from militia movement kidnappers. Along the way, she fell in love with the river guide and all-around nature lover Grant Coleman (Doug Savant). Now Grant and Alex are married and the remaining militia nuts are out for revenge.

“First Shot” will never win any prizes for deep dialogue or political insight, but it does manage to pack a lot of action and suspense in its two-hour running time. There’s plenty of time left over for Alex to look miserable in almost every scene. She’s particularly grumpy when Grant tries to plan their often-postponed honeymoon. Where the president’s safety is concerned, she’s all work and no smooching, and that sends her mountain man packing for a cold shower on a regular basis. I can see why the makers of “First Shot” want to portray McGregor as a capable and competent female action hero. I just don’t understand why she has to be such a sourpuss.

On “Last Resort,” (9 p.m., Sunday, Family) four couples travel to the exotic Kona Village Resort on Hawaii, not to compete for big prizes, but to work on their foundering relationships.

Yes, each of these four couples spends the whole time bickering, weeping and rehashing hurt feelings. How entertaining! But wait, it gets worse. Viewers get to watch each couple undergo individual and group therapy that includes role playing, slow dancing and daily progress reports to a confessional camera where each contestant rates his relationship on a scale of one to five. Unfolding over the next five nights “Last Resort” wraps up on Thursday when we get to see who reconciles and who breaks up. Using all of the hackneyed devices of “Survivor,” including contrived council meetings, dramatic tom-tom drumming and a Ken doll host, “Last Resort,” is pure torture the pop psychology equivalent of root canal surgery.

Today’s highlights

Women compete in the “U.S. Gymnastics Championships” (7 p.m., NBC).

Roger Moore stars in the 1977 thriller “The Spy Who Loved Me” (7 p.m., ABC).

Steve Irwin and his wife, Terri, grapple with Graham, a dangerous reptile, as they try to relocate him and his snappy girlfriend, Bindi, to a new home on the one-hour special “The Crocodile Hunter: Graham’s Revenge” (8 p.m., NBC).