Tess is first seen in the second season premiere episode "Wake Up Call". She is a paranoid schizophrenic living in a psychiatric hospital. She has mentally taken control of the patients and staff at the hospital to undertake a task of building an unknown structure. Once completed, an attempt at powering up this unknown device seems to fail, until Tess's friend and protector Kevin Burkhoff speaks for the first time in many years; he has been "woken up" by the device and is revealed to be the probable "father" of 4400 technology.
Tess is later seen in the episode "The Ballad of Kevin and Tess", when Tom Baldwin and Diana Skouris are looking for Kevin. Tess claims not to have seen him; however, secretly she is keeping Kevin at her house, as he has mutated due to his promicin experiments. Tess has also been instructing Diana to come to her house using her abilities so that Kevin could inject her with promicin. After the events that follow, Kevin and Tess run off.
In the episode "Terrible Swift Sword", Jordan Collier receives help from 4400s with the ability to trace people to track Kevin and Tess and discovers where they are hiding; he then goes to visit them and enlists them in his plan to steal Dennis Ryland's stores of promicin.
She uses her ability to prevent Richard Tyler from destroying the entire supply of stolen promicin in the third season finale "Fifty–Fifty".