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.

After a bomb leaves three people dead, the team presses a reluctant informant to gather information from his close friends who are under suspicion; OA and his girlfriend clash over where the informant's rights lie.

A fire at a boarding school shakes up Lt. Severide; Lt. Casey tries to help Dawson; Mills looks into his father's past.

The team must infiltrate a drug trafficking gang after the robbery of a chemical plant leaves two customs agents dead; Nestor offers his help on the case, giving Maggie new insight into his character.