When Ashling the Destroyer attacked Kinscaer, Tarcha's magic was strong enough to keep her at bay. However, Ashling distracted Tarcha for a few moments by igniting her hair by surprise. Before Tarcha resumed her concentration, Ashling killed the cenn Donal Alloway and a few other denizens of the doun. Tarcha then used her power to teleport Ashling to the edge to the world, where she cannot do any harm to the doun. Since Alloway's death, Tarcha was an Acting Cenn of Kinscaer.
Later, Tarcha was approached by the fae queen, Oona, who offered Kinscaer her protection against Ashling in exchange for the kithkin support in subduing her. Tarcha reluctantly agreed, believing that she is doing the best for her people. Sadly, Oona's help meant killing Tarcha and everybody in Kinscaer by her vines, and absorbing the kithkin mindweft power, as well as Tarcha's protective magic into her. Oona's simulacrum of Tarcha then greeted Rhys and his friends after their return, and later battled Ashling.