Crystal Kwon

In the stunning conclusion of a two-part episode, Meredith furiously works to save the life of a paramedic trapped inside an ambulance, as her sister, Lexie, holds the life of a patient in her hands.

A documentary crew visits the hospital six months after the shooting to document the road to recovery for doctors and patients; Meredith helps Cristina put on a brave face for the cameras.

It's Halloween, and the day is full of surprises for the doctors of Seattle Grace - Alex receives an unexpected and welcome visit from his former patient, Ava/Rebecca, Meredith is convinced that her mother's ashes are haunting her, and Cristina is snubbed by a surgeon she admires.

An ambulance crash endangers the lives of the paramedics involved, as Meredith and the Chief work on-site to save them, Bailey treats a patient who refuses her help.