Cynthia Ross
Cynthia is the doctor in Two Gardens but from ep 1 we see that she's by no means the caring, sensitive type.
Cynthia is a neurologist who's of the belief that science has yet to catch up with her. She is using Two Gardens to her advantage.
Hugely intelligent and ambitious with unclear and suspicious motives and goals, Cynthia is a mystery to everyone around her, including, sometimes, Edward.
She emerges as the knowledge behind Edward's plan and is, in short, very dangerous.