# rabbithole The narrow inverse of concept-family-explorer — takes one named concept and exhausts it completely, drilling down through mechanism, edge cases, and primary sources until a pass finds nothing new. Where [concept-family-explorer](/skills/concept-family-explorer/) maps everything *around* a subject, `rabbithole` moves *inward*: mechanism, sub-parts, edge cases, failure modes, the history of how understanding of the concept changed, primary sources, and where experts disagree — pass after pass, until a pass turns up nothing new. ## The six deepening questions Every pass asks each of these against every claim still standing: 1. **Why is this true?** — the mechanism underneath a stated fact. 2. **What happens at the boundary or limit?** — edge cases, failure modes. 3. **What's the exception?** — cases the general claim doesn't cover. 4. **Who disagrees, and on what basis?** — expert disagreement, competing models. 5. **What did the primary source actually say, in its own words?** — drift between original and paraphrase. 6. **What changed over time in how this was understood?** — historical evolution. ## Saturation, measured Each pass's claims are diffed against the accumulated list from every prior pass. The **new-information rate** — new atomic claims this pass ÷ total claims after this pass — is recorded per pass, and the run stops after **two consecutive passes** each score below 5%. A single low-yield pass isn't enough to stop on; it could just be an unlucky question angle. Two in a row, using a different subset of the six questions, is the corroborating evidence that the concept is actually exhausted rather than merely under-questioned. A pass whose new claims are mostly about a *different*, neighboring concept isn't saturation — it's a sign the "concept" was really a family, and the run hands off to concept-family-explorer instead of forcing a fake depth loop to continue. **Use it for:** "deepen my understanding of X", "exhaust X completely", "rabbithole on X". **Not for:** a domain or family, not one concept (concept-family-explorer) · one ordinary research pass with no forced exhaustion loop (`/dr`) · pulling a concept's mentions out of a corpus you already hold ([llms-concept-abstractor](/skills/llms-concept-abstractor/)).