Grey's Anatomy was in full tear-jerk mode during the "Till I Hear It From You" episode. Relationships were crumbling, death was ruining marriages, and Maggie's mom, Diane, was secretly battling breast cancer.
After Jackson repeatedly asked Diane to confide in her daughter, she finally spilt the beans the day before her mastectomy. Maggie was so hurt she was kept in the dark that she walked out of the room upon hearing the news.
Maggie came around right before the surgery and told Jackson to fix her mom. Unfortunately things got complicated after Jackson discovered Diane's cancer had spread and her prognosis was much more grave.
In the end Meredith stopped by to see how Maggie was doing and the tearful doctor simply said, "My mom is really sick."