Sun-young is a popular radio DJ with a big fan base for a cinema music programme that is aired live at midnight. She is a perfectionist who has built a successful career for the past 5 years, but when her young daughter needs surgery overseas, the single mum decides to quit. She prepares for her final show, from song selections down to the smallest details, but during the show, she receives a call from a listener named Dong-soo. He tells her that she must follow his orders while she hosts her live radio show and not tell anyone, or her family’s lives will be at stake. Without knowing what he wants or why this is happening to her, she continues with her 2-hour radio programme as things start to get worse. Here it is: the edgy thriller that exploded at the Korean box-office, trampling over the usual blockbusters from the U.S. ! Banking on a very tense cat-and-mouse game that made films such as Speed a success, director Sang Man Kim knows exactly how to tease your ticker, helped by his main actors : Su-Ae, usually seen in romances and dramas ( Sunny, Wedding Campaign ), finally gets the opportunity to hit some jaws, while Ji-tae Yu – from Into the Mirror ( which got its US remake by Alexandre Aja ) and, of course, Old Boy – plays the insane fan.