The hospital continues to operate despite the power outage. Meredith requires a C-section, which is performed in the dark; the baby is born healthy, but her earlier fall causes serious abdominal bleeding. Alex, Jo and Arizona must deal with chaos when oxygen machines in the NICU stop working. Cristina operates on Richard's patient by listening to his heart in the dark. The ER staff rush to help the passengers of a burning bus. April questions her engagement to Matthew when she believes that Jackson has died in the bus explosion. Callie finds out about Arizona's encounter with Dr. Boswell. Cristina breaks up with Owen. Dr. Bailey returns to the OR when she has to perform emergency surgery on Meredith. While trying to fix the emergency generators and restore the lights, Richard is electrocuted due to the water in the basement.