One night, Yoo Dal-rae receives a frantic call from her husband, Seo Dae-kang. "Sun Jeong is missing!" A wolf that Dae-kang takes care of has escaped from the zoo where he works as a keeper. Reluctantly answering his SOS, Dal-rae heads to the zoo, and they set out to search for the wolf. On the brink of divorce, they argue more about each other's faults than finding Sun Jeong, yet fleeting memories of their love resurface. As their emotions waver, Sun Jeong suddenly charges toward them.