Thefifth-yearresidentsreturnforthefirstdayofayearthatwillmakeorbreaktheircareers:MeredithfacestheconsequencesoftamperingwithDerek'sclinicaltrialandisterminatedatthehospital;ApriltriestostepuptotheplateasChiefResidentinthewakeofagiantsinkholeinthemiddleofSeattle;andCristinaandOwenarestillatoddsovertheirdrasticallydifferentfeelingsfortheirunbornchildccc