Anthropic's LLM. In this talk it plays the role of fictional archaeology assistant 'Rubyana Gems'. Louis used Claude over a multi-month journey to co-develop the substitution-cipher decryption code despite not knowing cryptography himself — an instance of vibe-coding a hard domain. Claude initially failed many times ('this will work' → gibberish) before producing a working generalized solver. Louis also tried unsuccessfully to have Claude evaluate near-complete (97%) decryption candidates locally and propose the final letter swap.