Hyung-do (So Ji-sub) wears a suit and tie like any other white collar worker... except his profession is murder. He is professional contract killer -- a hitman -- loyal to his employer and regarded as the best in the business. But one day, to the surprise of his colleagues and his enemies, he suddenly decides to quit his job for a woman (Lee Mi-yeon). Seen as the ultimate betrayal, Hyung-do is immediately hunted down by his former employers. Will he be able to escape with his life, much less with his love?