Vedette Lim

George O'Malley's mother comes to Seattle Grace for help after another hospital botches her surgery; a medical miracle inspires the residents; Jackson's suspicions about Mark and Lexie interfere with work.

Tori is asked to enroll at an elite performing arts high school.

Walter finally learns Cabe's long-kept secret regarding the Baghdad mission, and it threatens to tear Team Scorpion apart forever. Also, Paige's world is rocked when Ralph puts his life in danger to help the team.

The shooting of a child in their neighborhood forces Cruz and his brother to think about the gang; Isabella gets Mills to dress up for a gala; Casey feels sad he will be seeing Dawson less; Shay gets in deeper with Devon.

The firehouse crew goes to the scene of a railroad accident; Boden must make a big decision about his future; Severide learns more about the woman he saw with his father; Shay and Dawson continue to butt heads.

After a man is killed by an explosive package shipped to his home, the team attempts to capture the sender and intercept his latest deadly parcel; Maggie struggles to trust her younger sister.