Angela Lansbury pulls double duty Sunday night.First...

Angela Lansbury pulls double duty Sunday night.

First the Tony Award-winning actress appears in her CBS series, “Murder, She Wrote,” at 8 p.m. Then at 9 p.m., Lansbury stars in “The Shell Seekers,” a new TV movie airing at 9 p.m. on ABC (Channels 7, 3, 10 and 42).

The two-hour “Hallmark Hall of Fame” presentation boasts a serious theme. Based on the best seller by Rosamunde Pilcher, it deals with Penelope Keeling, a woman striving to resolve the troubled relationships with her grown children while coming to terms with her own life and the decisions she has made.

Patricia Hodge (pictured with Lansbury) portrays Keeling’s daughter Olivia, who is torn between a romance and her career. Anna Carteret and Christopher Bowen play Keeling’s other self-centered children.

When the trio discovers that their grandfather’s painting called “The Shell Seekers” is worth a fortune, they demand that Penelope sell it and give them the money.

Also in the cast are Sam Wanamaker, Irene Worth, Michael Gough and Sophie Ward.

Filmed in Cornwall, the Cotswolds, London and the Spanish island of Ibiza, “The Shell Seekers” was directed by Waris Hussein (“Edward and Mrs. Simpson,” “Princess Daisy”).