月落城少城主萧无瑕，忍辱负重潜伏梁国多年，化名为卫昭，背负佞臣骂名。卫昭为查清当年家族真相，试图掳走齐王案的唯一活口，但自己精心布置的计划却被突然出现的少女江慈所破坏。裴琰趁机将重伤的江慈养入府中，以求找到幕后“破坏者”。而卫昭的悲惨身世和民族大义也触动了天真烂漫的江慈，二人在相处中看到了彼此的闪光点，互生情愫。最终，卫昭、江慈、裴琰三人放下私人恩怨，共同对抗梁帝，实现了守护月落，建立清明天下的愿望……
A down and out cop lands the case of a lifetime when four suspects are nabbed in the assassination attempt of a prime time journalist. The case turns out to be a devious maze where nothing is what it looks like. The pursuit of it leads him to the dark netherworld - the 'Paatal Lok', and to shocking discoveries in the past of the four suspects.
