This thriller Korean drama revolves around Park Joo-hyung (Song Joong-ki). He was brought to Italy at the age of eight after being adopted by an Italian family. He then went on to become the adopted son of the late Don Fabio Cassano, the patriarch of a mafia family. Park Joo-hyung is subsequently renamed Vincenzo Cassano, now an Italian lawyer and a trusted adviser by Don Fabio—practically his right-hand man. 

However, after the big boss dies, his biological son, Paolo takes his place. It seems that he always had an axe to grind against Vincenzo, so he attempted to kill him only to be outsmarted. This encounter pushed Vincenzo to flee back to Seoul. He plans to recover 1.5 tons of gold that he stashed away in the basement of Geumga Plaza for a Chinese tycoon which he learned got recently deceased 

Unfortunately for Vincenzo, a real estate company under Babel Group has illegally taken ownership of the building and Vincenzo must use his skills to reclaim the building in order to recover the hidden treasure lying underneath. He also meets interesting characters that will also amusingly derail his plans. 

This retrieval operation, that only Vincenzo and his trusted confidant is aware of, sends viewers into a tumultuous journey from the very first episode. The entertainment value of the lead character’s struggle and other subplots in the series made it one of the most successful K-dramas of the year.