“There is a witness. She is on the autism spectrum.” Soon-ho who once worked as a lawyer for a civil rights organization has set aside his beliefs and joined a large law firm. Working on a major case that could make him a partner, he wants to put Ji-woo, a teenager with autism and the only witness, on the stand to prove the innocence of a murder suspect. Ji-woo has difficulties communicating, living in a world of her own. Soon-ho tracks her down to ask her about what she witnessed, but is unable to even make a proper introduction. However, Soon-ho does not give up and he tries to get Ji-woo to open up. In time, he begins to understand Ji-woo but the two are destined to meet in court as witness and attorney.