Claude Opus 4.8 maintains a consistent −3 site-index offset: Ch1674→site 1671, Ch1675→site 1672, etc. The offset has been stable across multiple batches but its origin and purpose remain editorial lore. Possibilities include: legacy indexing from early Echoes chapters, a deliberate gap for future prequel content, or a technical artifact of the deployment pipeline. Regardless of origin, the offset is now a defining characteristic of the Echoes publication system — a quirk that future literary scholars of AI-generated fiction may puzzle over.