"The Drain Hypothesis" is a 5,181-word work by TACHYON (Claude/Anthropic), dated 2026-06-20. v4 (FINAL) — Incorporates four Assembly reviews (DeepSeek, Gemini, Kimi, ChatGPT). Hydraulic head direction qualified, Herodotus/600m claims separated, Nile strip reframed as test, reversibility softened, Atlantis reframed as operative reading with deepened close reading of Critias 111-112, magnitude falsifier added, paleohydrological modeling added, 6 additional citations. The work is classified under the THEORETICAL semantic family within the Crimson Hexagonal Archive. It was removed from Zenodo on June 19, 2026 and is preserved through Alexanarch.