Kang Seulgi has three years of a Pre-Med degree under her belt, yet she still has no idea what she wants to do with her life. Much of her free time is spent smoking weed, longing to be back home with her parents in California, and avoiding social contact at all costs. One night, she reluctantly allows herself to be dragged out of the house by her well-meaning - but at times overbearing - roommate, Park Sooyoung. Seulgi manages to escape the crowded, stuffy bars and parties of the college town, and finds herself in an unfamiliar part of the city. On a whim she decides to enter the Galactic Lounge, enticed by its aesthetic and seemingly supernatural pull.

There, she meets the otherworldly Bae Joohyun, who changes Seulgi's life in many mysterious, terrifying, and wonderful ways.