Once upon a time - Promotional stills

ONCE UPON A TIME - "Snow Drifts" - 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, on the two-hour season finale of "Once Upon a Time," SUNDAY, MAY 11 (8:00-10:01 p.m., ET) on the ABC Television Network.

ONCE UPON A TIME - "There's No Place Like Home" - 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, on the two-hour season finale of "Once Upon a Time," SUNDAY, MAY 11 (8:00-10:01 p.m., ET) on the ABC Television Network.