 She was replaced in "Planet of Fire" by Nicola Bryant as Peri Brown, a serial which also marked the final appearance of Strickson and Flood.Davison was replaced by Colin Baker in "The Caves of Androzani" and Bryant was replaced with Bonnie Langford as Mel Bush, a few years later, after her character was killed off in "Mindwarp".Sylvester McCoy took over from Baker in "Time and the Rani" and Langford was replaced by Sophie Aldred as Ace at the end of the twenty-fourth season.