Ji-won tries to live a normal life, considering her lost memory as an umbrella left behind on the bus. However, her life in an unfamiliar world wears her out. One day, a haggard-looking Yu-jung shows up before her. 　　

A sudden appearance of her old friend with her eyes filled with fear… Which is better, knowing the past or living without it? The fragmented memory of her past drives her into the state of confusion. 　　

"Who am I?" 　　

Ji-won goes on a search for her friends, Yu-jung and Mi-kyung, puzzles to her broken memory comes back hard as she gets to the gorge. She shocked to find out about her true self, too different than now. A series of nightmares and phantoms exhausting her, she finds her way into the warmth of her mom. That night, she experiences the biggest nightmare. The revealing past, more frightening than reality itself torments her to the point where she can take it any more.