At the age of eight, Park Joo Hyeong left for Italy after being adopted. Now an adult, he is known as Vincenzo Cassano and employed by a Mafia family as a consigliere. Due to warring Mafia factions, he flies to South Korea where he gets involved with lawyer Hong Cha Young. She is the type of attorney who will do anything to win a case. Now back in his motherland, he gives an unrivalled conglomerate a taste of his own medicine—with a side of his own version of justice.

In a mythical land called Arth, the inhabitants of the ancient city of Arthdal and its surrounding regions vie for power as they build a new society.