Dr. Cassandra Railly is a fictional character from the television series 12 Monkeys. She is a brilliant virologist who becomes deeply involved in the fight against a deadly virus that threatens humanity. Her expertise in medicine and research plays a crucial role in the storyline as she navigates complex challenges. Throughout the series, Dr. Railly encounters various characters, including James Cole, a time traveler from the future. Together, they work to uncover the origins of the virus and prevent its catastrophic impact. Her character is known for her intelligence, determination, and emotional depth.