 Mulgrew played ambitious country singer Garnet McGee in a November 1978 episode of "Dallas".In 1979-80, she played Kate Columbo in "Mrs. Columbo", a spin-off of the detective series "Columbo", created specifically for her, which lasted 13 episodes.In 1981, Mulgrew co-starred with Richard Burton and Nicholas Clay in the Arthurian love triangle "Lovespell" as Irish princess Isolt, who casts a spell on Mark, King of Cornwall, and his surrogate son, Tristan.