Once Upon a Time S03 E21 Snow Drifts

"Magic is coming."

While Mary Margaret and David celebrate the naming of their son at a coronation in Granny's Diner, Emma and Hook are pulled into Zelena's time portal and find themselves in the Enchanted Forest of the past. But in their quest to discover a way back, they must be careful not to change anything or risk altering the lives of their friends and family - as well as their very own existence.