In the second segment of the "Trial" story arc, "Mindwarp", Peri was abducted by an arthropod-like creature named Kiv, who apparently transplanted his brain into her body. Soon after, The Doctor was led to believe that Peri was dead, and was severely distressed by this. It was later revealed, at the end of "The Ultimate Foe" (the fourth segment of the arc), that the evidence of Peri's death was faked by the Valeyard. In fact, Peri had survived, and been saved by - whilst also marrying - King Yrcanos of Thoros Alpha, a warrior king who had assisted the Doctor and Peri in "Mindwarp". It is not known what happened to Peri after she married King Yrcanos.