<p>In Vietnam, the return of case files for supplementary investigation and re-investigation is more than a technical procedural mechanism. It is also a semiotic practice through which courts articulate authority, redistribute procedural responsibility, and reshape the temporal flow of criminal adjudication. This study analyzes that practice not simply as a response to evidentiary incompleteness, but as a meaning-making act situated within the symbolic structure of criminal procedure. Using legal semiotics, legal discourse analysis, and argument-structure analysis, the study examines the 2015 Criminal Procedure Code of Vietnam, relevant guiding instruments, selected judicial decisions, and international fair trial norms as an interpretive frame. The analysis argues that file return performs a dual symbolic role. It simultaneously projects the court as the guardian of legality and procedural correctness, while legitimizing interruption, repetition, and renewed investigation within a system that formally commits itself to fairness, legal certainty, and judicial restraint. Through recurrent justificatory expressions such as insufficient evidence, serious procedural violations, and the impossibility of supplementing proof at trial, Vietnamese criminal procedure develops a distinctive legal grammar of delay and control. The Vietnamese experience thus contributes to a broader question at the heart of legal semiotics: how law generates the appearance of fairness not only through substantive rights or final outcomes, but also through the symbolic organization of procedural time.</p>