Cass is a character in The Fallen. She helps out in the Natural History Museum's sick bay with Maeve, Samira and Alexander. She is not as experienced with medicine as Maeve or Samira but has some knowledge on it as she has read many books on medicine. Alexander is her boyfriend.
Alexander and Cass were the first people to look at Robbie's wound when he came in. According to Samira, both Cass and Alexander are "mad keen" on organising and labelling stuff, she views it as their compensation for not being skilled doctors like her or Maeve, "They still had a lot to learn." Samira believes that they want to look like they know what they are doing, when she thinks they don't.