Kyung-ho meets his first love In-sook in 20 years and Ji-yeon, her daughter. After their encounter, strange things happen to Kyung-ho. Facing the past continuously, Kyung-ho realizes that he's locked in his own memories. 'Why is this happening to me?' To find the answer, he decides to walk into In-sook's memories with Ji-yeon. Meanwhile, an ant is crawling around in Kyung-ho's room.