Susan's story of her father's battle with Alzheimer's is pretty damn heartbreaking. For all the stupid and cruel things she does in this movie, it's understandable why she was willing to go so far to find a cure.
Susan: Tell me Mr. Franklin, have you ever known anyone with Alzheimer's?
Franklin: Well, no.
Susan: By the end all my father could do was ask why my mother wasn't at home, and each time I told him she was dead I had to watch him take that loss like a car wreck. 200,000 men and women develop Alzheimer's each year! What if you could end all that suffering with a single pill?
She continues to use her good intentions to defend her immoral actions when confronted with her culpability by Carter, but later on she is forced to destroy the cure when one of the sharks attacks her, frying it along with the hormone she previously extracted from one of the other sharks. Afterwards she slinks down into a Troubled Fetal Position.
Janice falling victim to the sharks as the others desperately try to pull her to safety, and her screaming she doesn't want to die. It's even harder to watch after seeing a deleted scene where she tells Jim that she thinks she's pregnant.
There's a deleted scene where Janice challenges Susan to name Jim's birthday or his favorite color and says that his father died a few months ago, but Jim didn't tell Susan to keep from distracting her from the project.
