Marlow Sweet was a member of Torchwood Los Angeles in the 1970s.

Marlow was valedictorian of her senior class and an accomplished astrophysicist. She had tried to convince her professors of the existence of space-time rifts through which aliens could pass, but was not taken seriously; however, she attracted the attention of Torchwood and was recruited for Torchwood Los Angeles.

While investigating Valerie Fox's disappearance, Marlow went undercover as Don Donohue's secretary. (AUDIO: The Dollhouse)