LOS ANGELES — Kelly Macdonald says TV viewers shouldn’t be discouraged by the subject matter of “The Child in Time.”

The TV movie, airing Sunday at 9 p.m. on PBS, is based on Ian McEwan’s novel about a toddler’s kidnapping and the aftermath. Macdonald and Benedict Cumberbatch play the parents.

Macdonald says the drama isn’t a crime procedural that dwells on the girl’s abduction. Instead, she said, it’s about relationships and love.

The Scottish-born actress’ other TV and movie credits include “Boardwalk Empire,” “Gosford Park” and the upcoming film “Holmes and Watson.”

Macdonald and Benedict Cumberbatch star as the couple whose world is staggered by the loss.

“This isn’t about a missing child and finding that child in a procedural (crime story),” she said. “At at the end it’s about love. … It’s nuanced and beautiful and uplifting.”

Nuanced applies as well to Macdonald’s body of work, whether as a bereft parent in “Child,” a woman threatened by a hired killer in “No Country for Old Men,” a gangster’s wife in “Boardwalk Empire” or, yes, even the naive maid she played in “Gosford Park.”

She’s playing opposite another outstanding British actor in “The Child in Time,” and found Cumberbatch “a dream to work with.”

“He’s so good, and I think we’re both quite generous actors,” she said. “I have worked with people where you give, and you don’t quite get back. … Some people just know what they’re doing and do it regardless of your intonation.”