An unconditional fan starts impersonating his new idol following his death.。特工林溪为执行最终任务，领养了会读心术的女孩萌萌，假借结婚潜入单家。而继承人单东郡实为卧底警察，亦在暗中调查。各怀秘密的“一家四口”相互试探又彼此扶持，最终携手揭露真相，将罪犯绳之以法。。
