A mad bomber forces a bike messenger to make a series of explosive deliveries in order to save the life of a famous pop star in this explosive action thrill ride. Gi-su used to ride with a motorcycle gang, but these days he just wants to earn an honest living. Using his formidable riding skills to become a bike messenger, he drops off a package at a local office building then watches in horror as a massive explosion blows it sky high. Shaken, Gi-su then picks up girl group singer A-rom, and prepares to transport her to a nearby television station. The moment his passenger puts on her helmet, however, a clock begins counting down, and Gi-su receives a call claiming that it has been rigged with explosives. Should Gi-su fail or refuse to deliver a series of bombs before the clock runs up, he and A-rom will be killed instantly. With time running out and the police at every turn, Gi-su blasts through the city streets in a frantic race for survival.