Love. As seductive and dangerous as magic, this potent, unpredictable force proves to be the ultimate weapon in the epic battle between good and evil in ABC's Once Upon a Time: The Complete Fourth Season. Soon after Emma and Hook unwittingly bring Elsa of Arendelle to Storybrooke, they encounter the mysterious Snow Queen, whose relentless obsession with both Emma and Elsa has chilling consequences. Meanwhile, it appears Regina has at last found true love with Robin Hood, but how will she react when her happy ending is thwarted yet again by a maddening twist of fate? Then, a banished Rumplestiltskin enlists the Queens of Darkness (Maleficent, Ursula, Cruella De Vil) in an insidious scheme to rewrite their own endings and corrupt the Savior by turning her newly blissful heart pitch-black. Relive all 21 thrilling episodes of Season 4. Plus, delve deeper with never-before-seen bonus features as you revel in the intoxicating magic and mystery of Once Upon a Time -spellbinding now... and forever after!