Kim Jonghyun, a retired marine, is suddenly back into operation when he discovers a plan of epic proportions that threatens to throw the world off balance. He works undercover and his job takes him places he didn't even imagine he would go, but it's also tearing his life apart. His lover Kibum, is suspicious he's seeing someone else because Jonghyun can't talk about his job. Now he has to save possibly the entire world, and keep his love life in check, or he'll lose everything.