Gavin leaves his mountain sanctuary to find his childhood sweetheart, only to immediately rescue the heiress Kyla from a lethal assassination plot. Forced into a marriage of convenience, he masquerades as a lowly security guard while dismantling billionaire conspiracies and shadow organizations. As he awakens his family's forbidden blade technique to avenge his father’s murder, Gavin discovers that the cold woman he’s protecting is the very girl who saved his soul years ago.