五百年前童氏一族因遭叛徒尹仲（徐少强 饰）所害遭遇灭族危机，幸得龙腾将军所救隐居于世。五百年后童战(杨俊毅 饰)，童心（张晋 饰）为救病危的父亲——童式族长童镇，违背了永远不得踏出水月洞天的族规，前往御剑山庄偷取可以起死回生的血如意。一番惊心动魄的争斗后，二人终于在长兄童博（于波 饰）的帮助下盗得血如意救父，并且阴错阳差的带了神偷豆豆（蔡少芬 饰）回到水月洞天。可出乎众人意料的是血如意并未发挥功效，而且血如意的意外摔碎冰封了整个水月洞天。族长童镇临终前立童战为族长。，死里逃生的几人就此踏上了寻觅解救之法的道路，更是意外结识了身怀秘密的 尹天雪(陈法蓉 饰)…

該劇圍繞三個家族五百年的恩怨，展開了一個迴環複雜、悲歡離合的傳奇故事。

自盤古開天闢地以來，童氏一族即擁有天賦異能，一向為朝廷所倚重。直至秦末，叛徒尹仲因心術不正被族人放逐，忿而煽動皇帝欲將童氏滅族，幸賴大將軍龍騰捨命相救，令童氏一族避入深山。童氏族長感慨浮生若夢，繁華過處不過是一場鏡花水月，因而將避居處命名為「水月洞天」，並嚴令童氏一族，永世不得出山。

童氏族人的護族寶物靈鏡，被龍騰將軍臨終前的鮮血所封，石化失蹤，而叛徒尹仲，亦被靈鏡所傷，身上留下了永遠無法痊癒的裂傷，時刻忍受折磨。

五百年後，童氏族長童鎮即將病歿，次子童戰，么兒童心，為救父親，私自離開水月洞天，潛入御劍山莊盜取傳聞中可以起死回生的「血如意」。長子童博（實為龍博，龍騰之後）聞訊趕至，救回正遭圍攻的童戰，卻誤把女扮男裝的小賊豆豆當成童心一起帶回。童戰見到族長父親最後一面，童鎮留下遺言：由童戰接任族長之位，讓童博離開水月洞天。

而大家辛苦帶回的血如意，被豆豆故意摔碎（試其真假），竟冰封了整個水月洞天。童博、童戰、豆豆和博學多才的神醫隱修，僥倖逃過一劫，四人不得不離開水月洞天，尋求解除冰封之法，並希望能找回失散的童心，因此一場愛恨情仇，驚心動魄的玄幻江湖紛爭即將展開。

Taking place in about 294 A.D., during the Western Jin era, it is the story of three young men, the Tong brothers, who live with their clan and family in a secluded valley protected from the outside world. No one in the valley has left it for five hundred years, ever since the mighty general Long Teng brought them there for protection. Since the dawn of time, members of the clan had used their gifts of divination, spiritual intuition and magic to serve the Emperors, but were betrayed by an ambitious, half-mad relative. Now, the boys venture to the forbidden outside world in search of healing magic for their dying father, discovering mortal danger, friendship, and passionate love. A branch of their own family remains powerful in the martial arts world, and an ancient enemy still lives.