Ben: Your sister won't be giving birth in three months, Juliet. She'll be dead before then. Her cancer's back. (He hands her a folder with the medical reports in it)
Juliet: Where did you get this?
Ben: Mikhail. I'm sorry. I should've told you sooner I just didn't see what good it would do.
Juliet: What good it would do!? I could've gone home! I could've been with her!
Ben: You still can. You can go home, Juliet. Be with her in her final days or you can stay here and help me with our problem.
Juliet: Why would I stay?
Ben: Because, if you do, I will cure your sister's cancer.
Juliet: I'm supposed to take that on faith?
Ben: You've been here for six months, you've done extensive work ups on all of us. Have you seen even a trace of cancer?
Juliet: That's here! And, being that you won't let me bring my sister here, I'm gonna -
Ben: Jacob said he would take care of it, himself. Unless, of course, you don't have faith in him. Every woman on this island needs you. If you choose to stay, I promise you, we will save Rachel's life.