When a judicial apprentice goes behind bars while on an undercover job, he uses his instincts to survive and get revenge.
At a high-end gambling house, skilled judicial trainee Kim Yo-han risks more than he can afford as Mok Jin-hyeong pushes him to bet even higher.
Amid the countless inmates out to get him, Yo-han finds a person willing to take a chance on him. He makes his debut in the prison’s underground casino.
Yo-han hones his gambling skills under the masterful guidance of a mysterious neighbor. As his confidence grows, he begins to target higher-stakes games.
Jang Seon-o begins mentoring Yo-han, while Song Du-cheol seeks retribution. Meanwhile, Oh Su-yeon moves to form a strategic alliance.
Seon-o asks Yo-han to spy for him, while Su-yeon investigates the mysterious death of Yo-han's grandmother and its connection to an officer's suicide.
Seon-o promises to teach Yo-han the art of deception if he helps him take on Yang Jun. Meanwhile, Nam Dae-mun sees an opportunity to take power.
Yo-han finds a man who may be the key to tracking down his grandmother's killer. Hong Jae-seon monitors Su-yeon and blocks her investigation.
Yo-han uncovers the secret forces aligned with the Yang brothers. Meanwhile, Jae-seon searches for legal grounds to raid the prison.
Pinned for murder and running out of options, Yo-han pledges his loyalty to Do Won-bong. Jin-hyeong cuts a deal with Yoon Byeong-uk.
Yo-han plays cards against the stockholders of a cosmetics company to sweep up their valuable shares and earn an invitation to a VIP after-party.
Yo-han navigates setbacks and close calls as he executes a multilayered scheme to escape from the casino and seize a massive slush fund.
After expanding his network and influence, Yo-han pursues his next target. Seon-o gets a chance to settle the score. The Goldman Casino cleans house.
Yo-han proposes an irresistible offer to Byeong-uk — with a catch. When Su-yeon finds out, their difference in opinion strains their relationship.
Yo-han builds strategic ties with government insiders, while Su-yeon maneuvers to strengthen her standing in the casino by aligning with former enemies.
The new boss in Macau targets Yo-han. Meanwhile, Cho Hae-do takes a hostage and the Yang brothers use intimidation to claim the manager's position.
Byeong-uk faces judgment, unaware of the consequences that await him. Yo-han offers his final opponent a last chance to turn himself in.