I have a crazy theory. What if Hee-Jae didn´t end his brother? His brother wanted out to live a"peaceful" life with his undercover cop wife. They cut off his finger as "proof". But it was just some other cruny they used as a body. That's also how Hee-Jae knows that Jin is undercover too. The wife told him that a new cop is being introduced to the organisation
I have a crazy theory. What if Hee-Jae didn´t end his brother? His brother wanted out to live a"peaceful" life with his undercover cop wife. They cut off his finger as "proof". But it was just some other cruny they used as a body. That's also how Hee-Jae knows that Jin is undercover too. The wife told him that a new cop is being introduced to the organisation