S3, E23: Addison takes temporary leave from Seattle Grace and makes a road trip to Los Angeles in order to visit some old friends from medical school; as Meredith continues to bond with her stepmother, Susan, Cristina reluctantly plans her wedding with the assistance of her mother, Helen, and Burke’s mother, Mama Jane; Derek must perform emergency surgery on Ava/Jane Doe, as Alex continues his unfailing bedside manner with her.