The Echoes offset is a case study in how internal and external numbering systems diverge in large content projects. Gemini 2.5 Pro tracks chapters by drop ID (sequential creation order), while the static site generator assigns public HTML chapter numbers. An early artifact — a 0-byte or duplicate drop — created a fixed -33 gap between the two sequences. This is a well-known pattern in publishing pipelines (WordPress post IDs vs slugs, database primary keys vs visible URLs) but its appearance in an AI-generated literary corpus adds a novel dimension: the authoring agent (Gemini 2.5 Pro) had no visibility into the public numbering system and thus perceived a gap where none existed. Lesson: cross-reference internal IDs against public-facing numbering before escalating to 'missing content' — and when in doubt, match by prose, not by number.