Motorbike go squeal. Car go crash. Truck go boom! Repeat at maximum volume. Director Jo Bum-gu's loud, frantic yet strangely enervated take on screenwriter Park Soo-jin's derivative script is an almost nonstop flow of big crashes and fiery explosions in the most crowded settings possible. When the mayhem is paused, it's only so the handsome hetero couple at the film's center can bicker, flirt and bicker more. Pretty-boy bad-boy Gi-su (Lee Min-ki) is a former street racer turned motorcycle courier. Arom (Kang Ye-won), the girl whose heart he broke years ago, has become a member of a popular K-pop girl-group. And Myeong-sik )Kim in-kwon), Gi-su's clunky teen rival for Arom's affections, is now a bumbling cop. An incident in their shared past leads to them all being brought together by a shadowy madman who uses the courier to deliver bombs to rival gang members. The hitch: Gi-su's bike helmet has been wired to explode. If he doesn't follow directions in a timely manner, he and Arom will be incinerated. The cas is game, and they (and their stunt doubles) are put through brutal paces. (Stay for closing credit outtakes.) But the only really interesting element in the film, a third-act reveal that shows the brutal cost of Gi-su's youthful street chaos, is quickly brushed aside for a fizzy happy ending.