Cass is the secondary protagonist in the Slender / ARG Series, 0nemoresoul2thecall.
At the beginning of the series, Cass is the girlfriend of college-student Sam, and the two live together. She helps Sam with her research on the Slender Man and goes to various places with her, such as Centralia and an abandoned mining tunnel. However, Alison, a friend helping them with the project, is mysteriously murdered, and the project is canceled.
Prior to Sam's possession, she is blamed to be responsible for it. However, it is eventually revealed that she has an evil counterpart of her own.
Cass is generally a caring person, however, she is easily emotionally broken down by the horrific elements around her and most of the time, acts rather cowardly, who the spirit possessing Sam blames her for. Despite this, she is determined to protect herself along with Sam by whatever means necessary.