She was sent, disguised through illusion as an old woman, to ambush a druid sent by the Mayena Circle before they could discover the truth about Fregenal's experiments. She mistook the warrior Korin for the person sent by the Circle and attacked him, but was killed by Korin in self-defense. When the actual druid from the Circle, Visenna, appeared, she used necromancy to interrogate the dead Manissa. The corpse uttered the words "Fregenal", "Koshchey" and "treasure".
Manissa was the mother of Mousesack. Mousesack's father left Manissa when the future druid was still a small child. Mousesack unwittingly teamed up with his mother's killer. Not knowing that Korin had killed Manissa, the young Mousesack befriended him and Visenna, who took him to the druid circle in Mayena.