No one is quite sure where Sheep came from, but Ace Andrews, after discovering the girl dying in the snow, has made it his responsibility to find out. While Sheep knows nothing initially about her former life, Ace trusts himself enough to take up the challenge. Together, the two embark on a convoluted mental journey to unearth Sheep's memories while Ace aides her in adapting to the outside world.  But nightmares and flashbacks slowly begin to surface in the back of Sheep's mind, and the implications of her visions and bizarre occurences in their everyday lives foreshadow events too sinister for her newfound friends to comprehend. Helping Sheep recall her former life quickly becomes Ace's highest priority, but each day brings another distraction to cripple their efforts. Though Ace feels he's gaining ground, the sinister nature of Sheep's past seems all too threatening, and they begin to wonder if her former life will beat them to their happy ending.