Seekers.

Seekers is a four-part TV mini-series released in 1992 about a police officer who disappears, and when his wife tries to find him, she discovers... another wife. They team up to search for him. It starred Brenda Fricker and Josette Simon, and was written by the celebrated novelist and screenwriter Lynda La Plante who also wrote the book of the same name. It was produced by Sarah Lawson.