Played by Sandra Bullock
Kate Mason was confined to a wheelchair since she was 6 yrs. old due to congenital disease and muscular deteriaration. She was high school friends with Oscar Goldman's nephew; Jimmy Goldman. This may have been how she was brought to the OSI's attention, although this is unclear.
She volunteered for a new bionic proceedure that could allow her to walk once again. Her bionics differ from her predicessors in that hers are implanted into her veins as well as her bones to allow for potential growth rather than actual limb replacement. Additionally, this approach didn't seem to require excessive rehabilitation.
A signal sent to the computer stitched into Kate's brain would send an electrical current to the various implants that would stimulate the muscles throughout her body. While the operations were many, the process took six months to complete; but the activation of Kate's bionic parts was nothing short of the flip of a switch.
Jamie Sommers was assigned to work with Kate as she approached the activation of her bionics. Kate expressed her doubts about living up to the expectations that thought others had for her. Jamie was able to counsel her and help her through her doubts. But, suspicion fell on Kate when their was an apperant security breach of the OSI during a formal event and one of the attackers was found to be bionic.
During the World Unity Games, Kate was given her first OSI mission and sent undercover as the American competitor with her Jimmy Goldman posing as her coach/trainer. Her activities as an OSI agent or otherwise after these events have not be chronicled (she does not appear, nor is she referenced, in Bionic Ever After?).