韩国情报机构NSS TF-A队，是一只实力颇强的情报队伍。队长郑柳建（张赫 饰）能力极强，但似乎暗藏着什么秘密；队员池秀妍（李多海 饰）拥有超强的射击能力，平日里虽然经常不在状态，关键时刻却能积极发挥自己的作用，是位不可或缺的女队员；而NSS的副局长崔敏则是美国五角大楼的超强出身，她奔走于谈判场合，是NSS改革团队的绝对核心。为了解决围绕在“白山”背后的谜团，NSS展开了一系列的调查和搜索，而故事的真相极其复杂和出人意料。队长柳建也不可抗力的被卷入了这些事情中，改变了自己的人生轨迹……
本片是《IRIS》的后续故事，第一部由李秉宪和金泰熙分别出演男女主角。

When Seol Gong Chan meets the lively and beautiful Joo Yoo Rin, he finds out that she has connections to his missing cousin, whom his grandfather has been searching for. He asks Yoo Rin to lie about being his long missing cousin until he can find his real cousin. She says yes, but soon their feelings for each other get in the way of their plans. Gong Chan's cousin, Seo Jeong Woo falls for Yoo Rin while Gong Chan's ex-girlfriend, Kim Se Hyun, a pro tennis player, tries to win him back. Will the two ever tell each other how they feel? Will Gong Chan ever find his real cousin?