This paper provides a single ingress into the Structura Reditus corpus. Its purpose is to replace the former three-part orientation burden with one complete front-door paper organized around placement, discipline, and first pass. The governing object is Reditus: the admissible return of structure through collapse under declared conditions. Structura Reditus is the field that studies that object. Generative Collapse Dynamics is the foundational theory of generative collapse and return within that field. Universal Measurement Contract Protocol measures Reditus through contract-first evaluation; Recursive Collapse Field Theory explores candidate structures, mappings, diagnostics, and closure paths before freeze; Unified Language of Recursive Collapse preserves meaning across language, pedagogy, translation, and domain movement; and Tier-2 closures translate domains into evaluable form without redefining the kernel. The paper proceeds in three internal movements. The first movement, placement, fixes the mature hierarchy: object, field, theory, authority architecture, functional systems, and domain ingress. This prevents the corpus from being read as an acronym stack and instead locates each layer by burden. The second movement, discipline, states why admissible return requires Axiom-0, frozen contract, bounded trace, closure availability, typed return, integrity accounting, missingness preservation, seam discipline, and three-valued stance. The third movement, first pass, gives the reader the shape of one complete evaluative route: an object is declared under one rule-set, read through drift, fidelity, roughness, return, and integrity, checked against closure, reconciled through the appropriate ledger burden, and carried only then to derived stance. The burden of this paper is not to restate the full technical corpus, prove the theorem inventory, reproduce the collapse-kernel reference, or replace the detailed casepacks and domain closures. Its burden is to make the corpus enterable as one coherent object. A serious reader should leave with the correct first order: Reditus is the object; Structura Reditus is the field; Generative Collapse Dynamics is the theory; Universal Measurement Contract Protocol is the measurement protocol; Recursive Collapse Field Theory is the discovery engine; Unified Language of Recursive Collapse is the language-preservation system; tiers govern authority; closures carry domains into evaluable form; and no claim receives return credit unless admissible return is demonstrated under declared conditions.