Season 1 follows Baek Kitae, an ambitious KCIA agent who's living a double life. Driven by his thirst for power, Kitae works as an agent by day and a smuggler by night. Smart, suave, cunning and capable, Kitae rapidly moves up the ranks after using his smuggling operation to consolidate power, protect his brother, and generate vast sums of money for the agency. Seemingly unstoppable, only one thing stands in his way — a tenacious prosecutor who can't be reasoned with, bought or bribed. With everything at stake for both men, follow the duo as they look to take each other down.

Having taken down the loan sharks, Geon U is more motivated than ever to pursue his dream of becoming a boxing champion — with U Jin now fully in his corner as his coach and chosen family. After grueling training and countless fights, Geon U finally claims the long-awaited victory, and the two soak in the roar of the crowd — until a new threat emerges that shakes their sense of invincibility. Enter Baek Jeong, who rules over an underground boxing league and crushes even reigning champions with ruthless ease. Driven only by money and violence, he sets his sights on Geon U as his next opponent. With the threat closing in, Geon U and U Jin brace for what’s coming. Once again, they’re pushed into a brutal fight to protect the people and principles that matter most.

Two young boxers band together with a benevolent moneylender to take down a ruthless loan shark who preys on the financially desperate.