gptkb:Callie_Torres_and_Arizona_Robbins_relationship gptkb:Meredith_and_Derek's_wedding
Alex Karev and Izzie Stevens' wedding
Arizona Robbins joins the hospital
Bailey's pediatric surgery interest
Cristina Yang and Owen Hunt relationship
Denny Duquette's return as a hallucination
Derek Shepherd proposes to Meredith Grey
George O'Malley's death
Izzie Stevens' cancer diagnosis
Lexie Grey and Mark Sloan relationship
Owen Hunt's PTSD storyline