S3, E5: Bailey treats a young mother battling breast cancer; Derek learns more about Mark and Addison's relationship; the interns defend a resident's competence at a staff meeting.

Starring Justina Machado,  Faith Prince,  Arye Gross 

S3, E5: Bailey treats a young mother battling breast cancer; Derek learns more about Mark and Addison's relationship; the interns defend a resident's competence at a staff meeting.