Three essays on a police officer whose public identity has been erased, a triad mole whose public record is immaculate, and the evidence that determines what either man can prove without determining what either man knows.
Infernal Affairs is often described as a story about two men who exchange identities. The symmetry is exact enough to power a thriller, but not exact enough to settle its moral problem. Chan Wing-yan has acted under a false identity for the police and wants ordinary life back. Lau Kin-ming has acted as a police officer for the triads and wants the life he built to become the truth. One seeks recognition of a history; the other seeks release from one.
These readings move from Yan's erased cadet record and compulsory therapy, through Ming's clean personnel file and his destruction of Yan's database entry, to the rooftop challenge and the archival copy discovered six months later. They ask how self-knowledge differs from legal identity, why present reform cannot be purchased by suppressing a claimant, and how a record can rescue the truth without repairing the life from which it was withheld.
Yan remains committed to the police mission while every public trace says he is a criminal. Knowing who he is does not give him the power to prove it.
Ming has a spotless record and wants to become the officer it describes. The past returns not as a label but as people whose claims he must silence.
A deleted database entry, a private copy, a recording, and a file found among a dead headmaster's effects reveal several different meanings of truth.
三篇写一个公共身份被抹掉的警察、一个公共履历毫无污点的黑帮卧底，以及那些能够决定两人各自证明什么、却不能决定两人各自知道什么的证据。
《无间道》常被概括成两个互换身份的人。这个对称足以驱动一部惊险片，却不足以解决它的道德问题。陈永仁为了警方使用虚假身份，希望拿回普通人的生活；刘建明为了韩琛扮演警察，希望自己已经建成的生活从此成为事实。一个要求历史得到承认，另一个要求摆脱历史。
三篇从陈永仁被删除的警校记录与强制心理治疗，写到刘建明干净的个人档案和他亲手删除的卧底资料，再抵达天台反问，以及六个月后从已故叶校长遗物中发现的另一份档案。它们追问：自我知道与法律身份有什么区别；为什么今天想改变，不能靠消灭昨天的权利主张者来购买；以及一份迟来的记录怎样能够救回事实，却无法修复被事实抛弃的那段人生。