Mother is a riveting movie. You can tell just by watching the trailer. Hye-ja is a single mom to 27-year-old Do-joon. Although her son is completely grown up, he is naive and dependent on his mother. He is therefore a constant source of anxiety. He behaves in ways that are foolish or simply dangerous. 

Walking home alone one night down a nearly empty city street, he encounters a young girl. He follows her for a while before she disappears into a dark alley. The next morning, she is found dead in an abandoned building. Do-joon is accused of her murder. Thanks to an inefficient lawyer and an apathetic police force, Do-joon’s case is quickly closed.  His mother refuses to let this be the end of the story. Trusting no one, Hye-ja’s maternal instincts kick into overdrive. She sets out to find the girl’s killer and prove her son’s innocence.